If the regs/TE members take it upon themselves to just hit random every once in a while, it'll help solve the problem. If it's still out of whack, force a scramble. No extravagent solution needed.
I don't think messing with the game mechanics/unlocks would solve anything.
Everyone does realize that when a player hits the "Random" button, it's not really random, right?
Pressing the random button assigns you to:
Red - when there are more Blu players than Red players.
Blu - in all other cases.
So if I want to play on the same team as kLine, and he's on Red, but I want to appear to be on a Random team, I just have to wait until Blu has more players than Red and press the Random button.
But assuming that nobody is intentionally being devious (aka working the random button), pressing Random doesn't do anything to solve the "Perceived" stacking.
Assume for a minute that everyone joins random, and there are two TE players on the server. Odss are 50/50 that they'll be on the same team. Even though they really joined random, it's still going to be perceived that they "stacked".
Also note that just because there are two TE players on that team, does not mean that the team is actually "stacked". Tsao and I could actually really, really suck.
I don't mind hitting the random button (and I do)...
but I'm still going Red on PL maps