I guess I'm so used to having Mel Gibson as Mad Max that I didn't really register that it was the same character.
And isn't that kind of the point, really? There was nothing in that movie that reflected Mad Max as a unique character, other than the "badass dude" heroic action-packed stereotype that we've seen represented in a hundred other movies. Hell, he talks so little in all of the movies that he might as well be one of those silent protags in an video game.
Wouldn't you want to see a prequel where you follow Q during college in similar vein to National Lampoon's Animal House as well as a developing issue with the patent office where he tries to file more and more outlandish and dangerous inventions until British Secret Service finds out and recruits him?
Imagine if they made a spin-off show from Better call Saul and named it : Saul - Chicken Run in a Winnebago and Saul barely showed up in it at all, maybe a few seasons in as a totally dismissable side character
People might get disappointed even if this hypothetical spinoff was quite good.