The problem is not that cavalry or ranged are too powerful, or even that there's too many of them. The advantages to being ranged or cavalry are obvious (even though people tend to overlook their weaknesses).
The problem is the autobalance system. It stacks teams too often with cavalry or ranged being heavily skewed to one side or the other.
Fix the balance system to balance based more on class (or items equipped) than on banner balance and score alone. Don't take out banner balance, make that the priority AFTER first making sure the classes are relatively balanced.
I notice it more when a STF clan of horse xbows gets on the server with the same banner and all 8 of them are always on the same team, and the enemy team has 0 horse archers/xbows.
Never thought I'd +1 huseby, but here I am doing just that. Although I personally feel that certain subclasses are OP (Such as highly agi-dominant archers), the classes themselves are not overpowered. I am no coder, but I cannot imagine that it would be a gigantic pain in the ass to code a simple system in which players who spawn with a bow are considered archers, players that spawn with a horse and a melee weapon are considered melee cavalry, and players that spawn with a horse and a ranged weapon are considered ranged cavalry. If we wanted the system to be even better, take into account the cost of the items and how heirloomed they are. I understand that there aren't that many developers of this mod, and most of them are working heavily on project asinus, but for christsake, we are not asking for any new models, animations, or anything of that ilk. Fix the autobalance system, and the mod is GREATLY improved. In fact, I'd wager to say that autobalance is the ONLY major problem with this mod currently, but it's such a huge fucking problem that it makes this mod absolutely infuriating to play a very large proportion of the time. Nothing like the team-score going 1-4 or 0-4 for several maps in a row, and instantly knowing beyond a shadow of a doubt if you're on the winning team or the losing team by the second round.