Actually almost all of BB's band memebers of all times were a bit of weaklings, if I may say.
I mean, when you look at them you know they all together easily lose to Primal Fear's singer, but from all of them I'd say Peter takes them all cause he looks like he can kill you not because he's strong, but because he's violent.
So I'd say NMF if you don't count The Wacken Carnage.