they used to attack thieves that stole from them, and die
Yeah, I remember how the slave would attack the thief, and then die by guards, too. Either make the merc only attack if it knows the thief is unprotected, or dialogue could possibly be added to make the merc/slave say something like "Hey! ____! Get back here!" "Where the hell did my stuff go!" or something like that when the thief fails, so that other people know that he is unprotected.
Suggested. I'm pretty sure they attack "Caught" thieves, so as they dont get killed by gaurds.
They already do this. (Yeah I just quoted myself)At least last time I tested....
Unless your merc has an M60, and the thief runs near a guard