Thing is, in many clusterfucks there is no way you can be 100% sure that the swing won't hit a teammate. It just happens. Well, let's just hope people stop pushing m when the teamhits are accidental.
I would still prefer to get a hp-penalty if you teamhit (Without the stun that is used in native, though).
To be honest, I don't know what's so difficult about fighting in a team. I have meleechars myself and I'm fairly active with my shielder atm. I can manage to fight with 3 teamates against one without hitting any of my mates. It's about timing and not about spamming to kill someone^^
HP penalty would suck, because accidents can happen sometimes and a kick is worse for people, because they might lose a multi or have to wait due to password, to play again.
One sidequestion: Did you change something about flag on siege? We just had it that 8 defenders were directly at flag, not too far away, but attackers won when time was over because there were still one or two attackers at flag as well.
Bug or intentional?