I was thinking that each tribe should have its own unit lines if possible. Each line would eventually converge onto a "General" unit, but this could happen sooner or later depending on the Tribe.
Heres the Aztek one:
Archers:
Slinger-----Plumed Archer-----Aztek Longbowman-----Tlecuahuitl
Warriors:
Jaguar Warrior-----Macana Jaguar Warrior-----Jaguar Champion-----Aztek Flintlockman (Dom's working on this now)
Spearmen:
Atl-Atl-----Elite Eagle Warrior-----Tlecuahuitl-----Aztek Flintlockman (Dom's working on this now)
Cavalry:
Eagle Warrior-----Elite Eagle Warrior
Mayans:
Spearmen:
Atl-Atl-----Javelin Thrower
Archers:
Slinger-----Plumed Archer-----Javelin Thrower-----Flintlockman(Generic)
Warriors:
Mayan Warrior-----Macana Warrior-----?------Flintlockman(Generic)
Incans:
Warriors:
Warrior(Generic)-----Inti Warrior-----Inti Champion-----Inti Flintlockman(Dom's working on this one)
Spearmen:
Spearman(Generic)-----Sapa-Inca Guardian-----Inti Musketman(Doms working on this now)-----Inti Flintlockman(see above)
Cavalry:
Llama Warrior-----Inti Llama Warrior
Iroquois:
Archers:
Native Archer----Native Longbowman-----Native Shooter/Boomstickman
Warriors:
Native Warrior----Tomahawk-----Beast Tomahawk----Native Shooter/Boomstickman-----Native Rifleman
Spearmen:
Guard-----Grizzly Warrior-----Native Shooter/Boomstickman-----Native Rifleman
Cavalry:
Mounted Warrior----Mounted Shooter
Sioux:
(Sioux Do not build the Warrior Line Until Guns become Availible)
Settler UU: Nomadic Horseman(1/1/2, required Horses), Upgrades from Settlers when Horses become availible
Spearmen:
Guard-----Grizzly Warrior(I wish something better was availible for the Sioux for this one, like Buffalo Spearman or something)-----Native Shooter/Boomstickman-----Native Flintlockman----Native Rifleman
Cavalry:
Mounted Warrior----Windrider----Mounted Shooter
Cherokee:
Warriors:
Native Warrior-----Brave-----Sword Brave-----Mace Brave-----Native Shooter/Boomstickman
Cavalry:
Mounted Warrior-----Mounted Shooter
Archers:
Native Archer-----Native Longbowman-----Native Shooter/Boomstickman
Spearmen:
Guard----Grizzly Warrior----Native Shooter/Boomstickman----Native Flintlockman-----Native Rifleman
Navaho:
Cavalry:
Mounted Clubman----Mounted Shooter
Warriors:
Native Warrior----Navaho Warrior----Knifeman----Native Shooter/Boomstickman
Archers:
Native Archer----Native Longbowman
Spearmen

Same as above Tribe)
Haida:
Warriors:
Native Warrior----Haida Raider(Can attack from the sea, same stats as Medival Infantry)-----Boomstickman/Native Shooter
Spearman

Same as above)
Archers:
Native Archer-----Native Longbowman-----Haida Archer-----Boomstickman
Cavalry: Mounted Warrior, Mounted Shooter
Ships:
Canoe----Haida Canoe-----Pahrump
(ALL native American Tribes can build Canoes, unless they have a better UU which replaces it)
Inuit:
Standard NA Spearman Line, Dog Sled Replaces Archer Line, as well as Mounted Warriors. Kayak Replaces Canoe.
Tupi(Civarmy can figure this one out)
Jes: Same as Above
Maphuche: Same as Above
(I will do the Modern Countries Next)