What you guys don't have considered is the question: Is it really important to know whether the dude you just killed was an enemy or not? Consider the situation in which everyone was forced to play like this, what would happen? People would still want to win, which means they would stick together and maybe even move in some kind of formations, to make sure enemies couldn't easily mingle among them and backstab everyone. The gameplay would change drastically.
There is no problem for archers. If you don't know whether someone is an enemy or not, you have two options:
- You shoot him and risk killing a friend, basically doing the enemy's work and lowering your chances to win
- You do nothing
It seems to be more prudent to simply not shoot if you are unsure. Then when you see that this particular dude attacks someone you remember or can easily identify as friend because of his movement pattern, or if he isn't attacked by someone you know is an enemy, you can start shooting.