you don't get rid of intentional tks, you just adjust the method of deliverance.
Now one person kills another one, he gets -1 all know who did it
Then one person steps into a strike intentionaly of a team mate, same result but harder to spot. Same problem with less deflection, the troll just needs to step more often into strikes of teammates.
Another example, Ranged guy shoots, targets move, teammates move, results in tk and self inflicted death through exident. While our front guy has an arrow in his head surviving, the shooter just falls out of his shoes 300 yards away where no enemies are nearby, how realistic is that?