I have seen many times where complaints have been made on one team having too many archers or cavalry, and I actually have thought of a solution.
Through the settings menu, you can set your character as a certain type, such as archer and cavalry. When auto balance occurs, an equal number of every class go to each team. If your character is not set to a Type, then he/she is automatically asked to set one. Until then, they are balanced in an undefined type. The only problem I see with this is that people can set to be what they are not, or that the majority of players do not set their type.
Thoughts on this?