My RTGG is very peaceful and shares his home with many fish and his best buddy is a 8" Baysnook and he is about 7". I also have a 4" GG and hes in with loads of other fish which he just ignores.
I've got one at work thats about a foot long and he is a terrorist.Coustemers love him(he looks really cool)but staff hates him as he kills any new fish in our 750gal.