It's like the people saying that Gane would win this fight never even heard of the Ngannou vs. Gane fight. Given how Ngannou, with bad knees, was able to win that fight on the ground without even landing any significant amount of real offense on the ground (or on the feet, of course), and given that Gane is remarkably unlikely to knock Aspinall out on the feet, the chances that Gane beats Aspinall are about the same as the chances that Jon Jones beats Aspinall in the UFC 317 main event plus the chances of Aspinall suffering a catastrophic non-contact injury during the fight.
Of all the potential opponents for Aspinall, Gane has by far the least chance to actually win, especially if he doesn't even know how his foot will hold up in a real fight because he's jumped straight into the deep end.