I feel like the Amazons would largely write off any hero who isn't Diana or tied to her (like Donna and Cassie).
The Amazons tend to write-off Man's World as a lost cause at worst or as troubled and misguided at best. Therefore they probably don't put much stock in the heroes of Man's World either. Especially when Diana so clearly surpasses 99.9% of them, and is arguably better than that last 00.1%.
Perhaps, after years of hearing about the exploits of Diana's peers, the Amazons might briefly tolerate the presence of Clark or Bruce if they absolutely had to. There was actually a Justice League Action cartoon that went into this; Lex Luthor and Circe team up to steal.....something.....from Themyscria, the Trinity show up to stop them, and Clark and Bruce are treated with barely restrained hostility the whole time (and the Amazons are that nice only because Diana tells them the guys are her sidekicks). Even after they stop the villains, Hippolyta barely manages a semi-polite "thank you. Now get out!" with spears aimed at both Clark and Bruce.
Themyscria prejudice is, and should be, a thing. That's one of the greatest flaws in their society, baked into the core DNA of the concept. I don't expect or want that to change easily or quickly. And more importantly, writers can use that to explore real world bias via allegory and bring up some social commentary without having to dive into real world issues. The Amazons should be a great society, but not a perfect one, and their distaste for mankind is the biggest and most easily used (from a narrative standpoint) chink in their armor.