Hapsburg? (is that already in the game?)
Florence?
Prussia? (is that already in the game?)
Austria-Hungary? (is that already in the game?)
South Africa?
Good call with Assyrians.
Prussia is Germany, Frederick has been a German leader.
Austria-Hungary and Hapsburgs are the same thing, and are very close to the Holy Roman Empire..
I think Poland would be pretty awesome, but Europe is "overrepresented" (politically correct way to make a bad thing out of "it's more important and had a greater impact on history"). By that logic, lets throw in the Chaddian Empire and the Uruguayan Empire and the Congolese Empire and the New Guinean Empire.
Also, Swedish Empire anyone? It was a huge power in Europe for about 100 years, with a very good army and near total control of the Baltic Sea.
1. Did the Civ in question make major contributions to human society (cultural, religious, architectural, military, etc.)?
Poland: Copernicus, occupied most of Central Europe..... I don't know what else.
Sweden: Huge military power in the Baltic, built forts, had lots of natural resources.
2. Was the Civ in question independent for at least part of its history? Are they different enough from previously included Civs?
Poland: Yes, through the medieval ages and renaissance, and when they did get occupied they fought like hell.
Sweden: Yes.
3. Can a definitive leader, city list and unique unit be chosen for the Civ? \
Poland: Jan Sobieski, Winged Hussars, and a capital city named WARSAW!
Sweden: Gustav Adolf, probably. For unique unit, Horse Artillery would be pretty cool.