I like Mike, but by no means an easy fight. Norris would, together with Curry, be the best boxer Mike faced at 154. Clearly better than for example McCrory, who gave Mike some problems in the early rds.
The Norris of the Brown rematch would have a very good chance here. After a few heavy hitting performances Norris' power went to his head and was imo responsible for his loss to Brown. Norris' speed would make it extremely hard for McCallum to counter him and set him up over the long haul. Here i go again but i believe McCallum has become a bit overrated i really do. He's got some beautiful old school moves and is very good technically but he can absolutely be outboxed by someone speedy. I think Nunn would be an absolute special for example.
Nunn would be very tough for Mike, no doubt. I have doubts over the pace he could keep over 15, though.
McCallum by mid to late rounds stoppage. He's too strong and resilent. Norris would probably build a lead, but would get caught. A patented McCallum body attack would probably start slowing him down and then McCallum would pour it on to get the tko.
I have Floyd Patterson, Terry Norris and Michael Spinks as the most underrated fighters in fantasy fights. Terry Norris had a big chance of beating McCallum in the same style that Kalambay did, since Mike struggled a lot with movers, if Terry keeps his game plan i can see him winning a decision.
McCallum would be tougher over 15, absolutely. I don't think Nunn or Norris would have ever been in a scheduled 15'er. Nunn at his best definitely shines over 12 vs 15. Norris would go 15 better i think than Nunn. Having said that McCallum, his body work, pace and style are almost made for 15 aren't they.
Yes, I think 15 rds was a good distance for him. He was a fighter that liked to build an foundation in the early rds. It would be even more so against elusive fighters like Nunn and Norris.