If you kill 1 rat, the other though do not turn against you.

You know if you use the statuate of a cat and run near a dog,the dog doesnt turn hostile,a boar doesnt turn hostile.

However the funny thing is a boar will attack you in your usual form but wont attack the guard.

A troll hunter will attack you unless you are near the vicinity of another troll,in which case the troll hunter will attack the troll,the troll will attack you and you get to choose who you attack.