here's what I think about most of the factions

French-95% of the time are the strongest and richest country on the map
Alhomads-they always expand far into Europe, until they meet france or me
Egyptians-in the normal version they do well, in the XL mod they get beaten up by the crusaders
Mongols-do very well at the beggining, then stop at polland
Danes-usually expand into the eastern part, into russia and mongolia
Germany-gets beat up by everyone
England-france kills them
Byz-do good in early, but in HIgh and Late get owned badly
Russians-I usually play as them, so I don't really know how they do

thats my 2 cents