What exactly are all these flashes Morton had in singles? I recall one or two good/great matches against Tully and a couple overrated matches against Flair. Eaton had a better singles run in 1991 alone.
I would rate Michaels above Morton. But I prioritize guys who work 20-30min singles main events over tag workers. Morton was great at what he did, but I think it's more difficult to work great singles matches than tag matches adhering to a formula. Not to mention Michaels was a great tag worker himself.
Which of the Flair matches have you seen?
Off the top of my head there's also the Lawler match from Louisville in '79, the Sonny King WMC studio match from '80, and various singles matches as part of tag feuds, but he was a tag team guy for most of his career, whether it was with Eddie Gilbert, Ken Lucas, Robert Gibson, Tommy Rich/Terry Taylor, or Gibson surrogates like Chris Hamrick on indy shows. And all of those teams were awesome in their own way. I suspect we'd have more singles matches if we had more '79-'81 Memphis, though (and I think there's some house show footage that's out there but not currently circulating with a bunch of Morton).