They added champions as a way to do two things. 1. Force new weapons to be used and 2. To try and make people work as a team Overloads primarily focus on 2 since they heal at insane rates unlike the other two though they can be a bit annoying when they jump platform to platform which blocks stuns
The solo lost sectors are the problem the Overloads do not stun for long and some times just get right back up and or heal even though stunned.. since they can't seem to make them not buggy and work as intended either give us a better way to stun or dispatch them or remove the plague. At the rate things are going if Champions are in Witchqueen I might not even bother playing.