It depends on what level of dickhead they are. Personally I'd take Johns (used drugs but it never came to light til after and it was never anything abusive), Thurston (what did Thurston do?), Meninga (dickhead but didn't really do anything wrong), Teo (cleared of all charges). I'd even take Carney 'cause he has fully redeemed himself.
I wouldn't take Robert Lui (admitted to assaulting girlfriend.. twice), and until Fergo is cleared of all charges and proves that he will not do anything stupid again, I wouldn't take him either.
Think of it this way. You are given a nuclear reactor. You can either have a reactor that has been repaired and will give you a solid output for a long time. Or you can have a reactor that has a higher output but is unstable and may blow up taking your season with it.