Long story short: There isn't really any autobalance.
One way people circumvent it is to just NOT SPAWN if they get on the team that they don't want to be on, so the teams might be perfectly balanced, if they would spawn without being on their clan's team.
Happens all the freaking time. Good solution to that, though, might be to not reward players who could have, but didn't, spawn in. Maybe even an auto-kick or temporary ban for repeat offenders.
Admins sometimes take care of it but not usually.
Unfortunately I think the only solution to this would take more effort than it's worth, though the autobalance for c-RPG is way worse than native, where it seems there's extensive balancing done every round.