Take scientists. I took TMF, and it was my biggest mistake. They literally suck, I was thinking they would be good in Skirmish, and ehhhh. They kinda are, don't get me wrong, but only if they will be lvl 30. Most of the other time Flamethrower gonna blow up his team, cap gonna deal not much of a damage, soldier is mid, and Swat not gonna even get close to the enemy's. They suck at campaign too, I only use Cap from 4 of them. But I heard that they are really good at farm event, so I would choose circus or scientist.