I looked and Wowpedia has this awesome old school looking map of Warcraft: Orc & Humans.
Wowpedia also says there are 12 Warcarft Orcs & Humans Missions for each race (so 24 in total).
- Regent - As a test of your abilities, the King has appointed you as Regent over a small parcel of land. Since we must keep our armies in the field well supplied, you are to build the town into a farming center of no less than 6 farms. Construction of a barracks for defense is also advised, as our scouts have reported Orc patrols in the area.
- Grand Hamlet - The Orcs around Grand Hamlet are becoming increasingly brazen in their attacks, and our spies inform us that they are amassing a large army to march against the town. The King is sending you, along with a small detachment of troops, to rally the people and defend the town against all opposition.
- Kyross - With Blackhand's raiding parties routed, now is the time for us to secure a lasting peace in the area around Grand Hamlet. You must seek out the Orcish outpost of Kyross that lies deep within the Swamps of Sorrow, and destroy it.
- The Dead Mines - It has been some twenty months since Sir Lothar, one of the crown's greatest heroes, led an expedition into the Dead Mines to search for the Lost Tome of Divinity. They were never heard from again. However, the great knight has recently appeared to the Abbot of Northshire in a vision - battered and pleading for assistance. King Llane has ordered you to lead a detachment of warriors and healers into the mines in an attempt to find Sir Lothar, heal him, and bring him and any other survivors back alive.
- The Forest of Elwynn - The Forest of Elwynn is a strategic key to securing the Borderlands. An outpost near the southeast edge of the forest will serve as your stronghold. The King has assigned one of his knights to aid you, so that your task of ridding the area of Blackhand's dark minions may be more readily completed.
- Northshire Abbey - The monks of Northshire Abbey are under siege by a band of warriors that have been convinced by enemy agents to fight against the crown. You will be given a complement of knights to lead to the Abbey, which is already under attack. Ride hard and fast, as you must prevent its destruction. When you have secured the Abbey and beaten back these treacherous curs, you must then move to destroy the enemy at their source.
- Sunnyglade - A raiding party has completely overrun the village of Sunnyglade. Our scouts report that the survivors have been taken to a hidden Orcish compound to serve as slaves. You must take a detachment of warriors and rescue the group of peasants that are imprisoned somewhere in the Orc camp. Our intelligence confirms that all of the prisoners are together, and that you must destroy the enclosure to open a path for their escape. The rebuilding of Sunnyglade is also of the utmost importance, as you will need their assistance in destroying the Orcish slavers.
- Medivh - A new crisis has arisen that threatens to end the lives of all who would serve the King. The evil warlock Medivh has begun draining the soul of the land itself to increase his dark powers. You must take a party into his tower and destroy him before he summons enough energies to devastate all who would oppose him. Beware his mastery of the black arts, for legend speaks of his ability to command daemons of Hell.
- The Black Morass - The time has come to take the battle into Blackhand's own domain. King Llane has ordered a full assault upon the Orcs, demanding that this plague that spreads across the kingdom be eradicated. To the east of the Borderlands lies the Black Morass where the Orcish hordes make their encampments. You are to lead an army into this foul region and destroy every trace of their dark presence.
- The Temple of the Damned - Runners have arrived and informed you of grave news. King Llane lies dead this day, assassinated by the treacherous Garona, at Stormwind Keep. His last command was that you should assume the mantle of War Leader, and end this battle that has drained the land of its resources, and now its king. Scouts report that deep within the Black Morass lies one of Blackhand's darkest seats of power --- the Temple of the Damned. No peasants dare approach the vile temple, and only the bravest of your soldiers have agreed to accompany you on this mission. You must strike boldly and without err, for there will be no reinforcements.
- Rockard and Stonard - Here beats the diseased and malevolent heart of Blackhand's plagued lands. The sister towns of Rockard and Stonard are all that stand between the forces of the kingdom and Blackhand's stronghold - Black Rock Spire. After conferring with your warchiefs, the path to victory lays clear. You must destroy Rockard and Stonard, thereby cutting off all lines of support and supplies, so that the final offensive can be made upon Black Rock Spire.
- Black Rock Spire - Black Rock Spire stands before us! The skies above the reeking swamp fill with the gathering thunderheads that spell doom for the loser in this final confrontation. Tension hangs like a heavy cloak on your shoulders as your troops prepare for the battle ahead. Above the din and chaos that swirls about the battlefield stands the Castle of Blackhand, its gaze sweeping down upon the battlefield where the destiny of the land will be decided. Destroy the stronghold and those who would seek to defend it, and Azeroth will be freed from Blackhand's poisoned grip forever!
- The Swamps of Sorrow - Blackhand has assigned you to an outpost in the Swamps of Sorrow. Your task is simple enough that even the War Chief feels that you are capable of it. Construct at least six farms, so that we may keep our troops well fed and ready to do battle. Only a fool would leave his treasures unguarded, so you must also build a barracks for the defense of these farms.
- The Borderlands - Like the stinging of a wasp, the attacks from the humans grow more and more bothersome. You have been assigned to a small outpost on the Borderlands of the Swamps of Sorrow. You are to defend our lands from the incursions of these ravenous dogs by crushing any opposition that you encounter.
- Grand Hamlet - The Humans are growing strong in Grand Hamlet. An outpost will be placed under your dictatorship to use as you see fit. You must then prepare and lead a force to destroy Grand Hamlet and all that dwell there. Blackhand will brook no survivors - these Humans must be taught a hard lesson in the ways of humility.
- The Dead Mines - You are wakened from your nights[sic] sleep by a runner from the War Chief. Blackhand's daughter Griselda has run off with the outlaw Turok's band of Ogres. Our wolfriders have tracked them to the dungeons hidden beneath the Dead Mines. Find Turok's band of rebellious pigs and kill them all --- including Griselda. She must not disobey the commands of her father... ever again.
- The Red Ridge Mountains - On your return from the dungeon, you receive word from advance scouts that the recently established outpost near the Red Ridge Mountains is under siege. A group of raiders have been dispatched to assist you in taking back the outpost and crushing the Human opposition. Your secondary objective is to seek out and completely destroy their encampment, putting an end to this threat for good.
- Sunnyglade - The Humans of Sunnyglade have become fat and lazy with their prosperity. The town is like a ripe plum waiting to be plucked. You will march upon their weak Human armies and smash them to pieces. Somewhere in the town is a tower that you must keep intact so that we may study how their magiks are created. Fail me, and I will have your head on a pike at the gates of Black Rock Spire.
- The Black Morass - The time has come for you to seize control of the Orcish hordes for yourself. Blackhand has become foolish in the deployment of his personal troops, and has left an opening that you can now exploit. A key outpost in the Black Morass is the core of Blackhand's supply lines - not only to his foremost battle groups, but to his castle at Black Rock Spire, as well. The complete destruction of this outpost will disrupt his power base long enough for you to secure his overthrow.
- Northshire Abbey - The destruction of Blackhand's outpost has left him in a weak position. The Shadow Council, sensing your rise in power, orders the assassination of Blackhand and elevates you to the position of War Chief. A wolfrider brings you news that our best spy, the half-orc Garona, has been discovered by the Humans of Northshire Abbey and imprisoned there. She has valuable information concerning new and powerful magiks that would aid you in the destruction of your counterpart - King Llane. Trusting no one to complete this vital mission in time, you must find her, and then completely destroy the abbey to protect her secrets.
- Northern Elwynn Forest - With your new found magiks, the time is ripe to burn the Human occupation from our lands. There are two Human outposts to the south that pose the greatest threat to our security. Reports from scouts near these towns show that the key to your success in this confrontation is to hold back the Human forces at their bridges while you strengthen your attack force. The glories of combat will be yours as you personally lead the armies that will reclaim your homelands.
- The Center of the Human Lands - You have tasted victory, and the craving for more is upon you. It is clear that one decisive blow to the Humans will make the total and complete domination of this race a simple matter. Your spies have gathered intelligence that points to an encampment near the center of the Human lands where their knights and soldiers are sent to train. Although they will not be expecting an attack, they should prove a good fight. The destruction of this site would greatly weaken their forces, and etch your position as War Chief in stone. None shall survive!
- Goldshire and Moonbrook - The final march to King Llane's home, Stormwind Keep, is at hand. Only two pathetic settlements stand in the way of the awesome juggernaut your cruel leadership has created. The Humans have proved to be amusing opposition, but the hour of doom has come for them. The complete and utter destruction of the twin cities Goldshire and Moonbrook will sever the lifeline between the King and his people, making him a figurehead waiting to be lopped off.
- Stormwind Keep - Stormwind Keep is ours to take! The Orcish hordes gather like buzzards to carrion, as the moment of destiny is close at hand. A low growl fills the air as your wolfriders whip their savage mounts into a frenzy. The earth shakes as catapults are loaded and moved into position. The fires of the burning rubble about you dance in your eyes as you gaze upon the pristine, white towers of Castle Stormwind. White that will soon be washed with the red of King Llane's blood. With his fall, all of Azeroth will be yours!
Do you think it would be possible to use both sets of missions at the same time, with something like the Social Collapse Points system, from Night Below being used to decide if the enemy are able to advance, while the PCs side is advancing (if the PCs are not up against the enemy)?
For example the 4th Mission for both sides is "The Dead Mines", so those two groups could both try to explore The Deadmines at the same time. That could give you extra NPCs to deal with.
But the 6th Mission for the Humans is Northshire Abbey, and the 8th Mission for the Orcs is also Northshire Abbey. So maybe Human PCs could drive disloyal warriors away from Northshire Abbey in their 6th adventure, only for NPC Orcs to attack Northshire Abbey two adventures later (when the Human PCs have been sent to deal with the evil warlock Medivh).
I'm not too sure how the two opposing adventure paths would fit together, but it could create a sense of the world changing around the PCs if they were off adventuring and orc adventure parties were doing the same thing.
It looks like there is an entire war there, with both the campaigns ending with the other side being totally defeated. It's probably not going to be possible to do both endings together, but if the Social Collapse System came into play, that could be used to allow the PCs to decrease the victories of the other side. So maybe the two sides of the campaign could be influenced by the PCs, even though they might not be dealing with the opposing party of NPCs directly.
It does look like The Deadlands would be a great opportunity for the PCs to directly or indirectly encounter enemy NPCs who get away. (If they kill some NPCs, then the GM can swap them out for whichever ones escape. So whoever the PCs kill turn out to be high placed minions. Maybe the GM can keep it all a bit vague before Mission 4: The Deadmines...and allow the PCs to come to the conclusion of who is working against them, for themselves.) The opposing group could leave behind some sort of sign, every time they carry out one of their NPC missions. And that could be a way to make it personal.