Honestly I do think Randy was a pretty big "right place right time" guy at HW, an injuried Sylvia and first to explose Gonzaga and Vitors flakey nature.
When he really went toe to toe with top HW's in prolonged matches such as Barnett, Ricco and Lesnar he lost, the best wins of that kind he had were Randleman and Rizzo and IMHO they caused him big trouble dispite being a level below the very best HWs.
You put Randy into Pride and honestly I think he struggles to be top 10 at HW, Fedor, Nog, Crocop, Barnett and Sergei I would be pretty confident beat him plus I would favour Aleks, Werdum, Hunt, Herring, Semmy, even Fujita I think would have a good shot. The issue for me is lack of finishing ability/chin, Randy could only wear any of those guys down and they just need to land once or get in a good position once.