Then I apologize. Although I still disagree with giving them weaker infantry, if it is just for the Franks that is much more reasonable. Although I would think that it would make more sense for the Franks to get their best infantry early, like the barbarian factions in vanilla RTW, but these aren't as good as the ones the other factions get later on. Meanwhile their cavalry gets progressively better, leading to cav heavy armies.
Again I apologize for my misunderstanding, as I am just trying to help (in my own, cynical, way... I guess).
"The only one here who could possibly help us is Edorix. Unfortunately, he is busy off killing Romans right now."- GundamMerc (an imagined quote)