Crowe's performance against the best of his era isn't in dispute at all. It's how he did against the next tier that's at issue and impacts on his average. England at home and away, for example.
Not that I think average is (nor should be) the sole measurement of the quality of a player. If you dominate mainly the best sides, that's an extremely useful player to have in your side and I definitely put him ahead of D Jones in terms of when he scored as Jones' average is boosted somewhat a lot of 2nd-dig/late series nothing runs. I also don't believe that averaging 50 magically makes you a better player than someone who averages a few runs less. What averaging 50 says (broadly) is that you scored the hard runs and the easy ones. Since Crowe was mainly at his best in the former situations, his average takes a dip. Doesn't mean he wasn't a batting genius.