If two people attack you they will both go grey. If they stagger their attacking and wait till you finish the first guy before jumping in, well going grey isnt going to change this situation any. Case and point, I was attacked last night by a pair of players while I was out and about hunting clades. They were both on desert horses with heavy armor, I was on a steppe horse with no armor. They attacked first and went grey. I not only managed to escape but I managed to mercy one of their horses while not losing my own, or having to enable criminal actions.
There was some luck and some skill involved in that encounter, but that isnt the point. The point is I didnt have to enable criminal actions to deal with either of them.