They need a send off rule. Better still, a send off rule that also does not allow another player on so the team needs to play one down. Soccer does that. Even Rugby League has a "sin" bin where the team is one down. Ice Hockey does it for any penalty I thought.
If a dude smacks out another player, breaks their teeth well heck, why is that guy still on the field? just not right. AFL administration are a bunch of idiots.