All of these fighters were either done or above 160 when Hopkins entered his prime, and peak Hopkins beats all of them prime for prime.
If Hopkins is allowed to headbutt, grapple, hug, and whatever else he gets away with then he definitely has a great chance of being competitive. However, in a fight that is fought within the rules, he probably beats Johnson, but is slightly the underdog against Nunn and McClellan.
I guess greats like Jack Johnson, Sandy Saddler, Archie Moore and other greats wouldn't be as good either, since hopkins borrowed a little tricks from them in terms of the clinching he does and how he rough houses his opponents which is an effective way of neutralizing and smothering an opponents punches and breaking a fighters rhythem flow of punches.(which was very effective against Calzaghe, Joppy, and Keith Holmes) Maybe you should do a history check on a lot of the fighters of the past before you bash hopkins. It's not his fault he's more versatile and well rounded than the average fighter in the history of the sport.