It’s not that they’re a dead weight, it’s that they deliberately choose not to play in order to increase the chances of the game being lost.
Your solution would work, as would many others proposed against smurfing (cf. part V). However, ultimately it comes down to how much the devs see smurfing as an issue, and if they are ready to do something about it. So far, M1-GM leagues put aside, the previous team didn’t seem to be in such state of mind. 