But it does point out as to when they were in or surpassing Nunn's class, which you questioned in your original observation.
I think you might be in a minority there. Not least as because you pointed out, he improved so much defensively. He was not as offensively exciting, but that, with no hindsight, was clearly going to need to change if he was to have a worthwhile career in the 90s.
I'd go with McCallum. I don't think it's a given Nunn ever has the heart and stamina to keep McCallum, Benn and Eubank from grinding him down given how he performed with Toney, Barkley and Starling. Nunn for me had weaknesses with his foundamentals.
Nunn and McCallum are one and two. Kalambay, Jackson and Watson are in competition for number three. I say Watson. Eubank and Benn shouldn't be mentioned.
They didn`t surpass Nunn`s peak, Benn did well to beat G-man and Eubank beat Benn and Watson and drew with Benn, McCallum was far more impressive v Watson, I`m not sure Benn and Eubank at their peaks could have beaten Tate.
Watson wouldn`t have beaten G-man, Kalambay beat McCallum once while Watson was out-classed by McCallum.
Watson was weight drained and inactive for McCallum. I highly doubt he'd have beaten the version who fought the Eubank rematch. And don't be ridiculous, Watson would have absolutely beaten McClellan.
I saw peak Tate; Olajide was good, but he made a meal of beating the washed up Sibson, and could not cope with Nunn. Eubank and Benn would be even bigger fights, and I do not think Frank would be comfortable with that.
Nunn was #1 at that time. I wouldn't even have Eubank or Benn among world top 5. Neither were they even top 2 in the UK (Graham and Watson were). Contrary to the revisionism popular on this board, it wasn't a particularly strong era for middleweights. Better than what we have now, of course, but relatively weak historically speaking.
Not much between Nunn & McCallum. Nunn just ahead - with McCallum following by a hair. Nunn carried the Kalambay KO and the Barkley win into the decade, but McCallum performed better than Nunn during 1990, in my opinion.