I usually hunt unity but today a friend of mine was low of 7.62 ammo so we hunted raiders.
We wiped out 12 gang of raiders ever with the same tactics, we walked so close we could kiss them, counted until 3 then we bursted them , killing the survivors and looted.
Raiders never tried anything hostile against us.
They awaited that we open the fire with respect and resignation.
500 7.62 ammo and many fal after my reputation dont lowered.
Someone telled me that ncr army do the same.
So my suggestion
Raiders (and enclave) should be hostile to everyone (save if you become a member), if this is too much at least they should do like Unity ( and so should do ncr army).