Cav isn't the problem (it would be archers if it wasn't cav), it's that the teams are unbalanced and you have 20 cav on one side (or 20 archers) and 5 on the other team.
We've seen this before in NA1 when you have 10 SemenStorm Horse Crossbowmen on one team, and the other team has no horse crossbow or archers.
The balance system should TRY to balance by banner, but if one side has too few of a class, it should take from wherever it needs, in order to balance it up.
The team balance system is the problem. I like playing with my clansmen, that being said, our enjoyment shouldn't take precedence over everyone elses. The only game I've ever seen a pub stomp not only be accepted, but actually encouraged, is c-rpg.