I mean i gotta disagree I don't like the concept that some places just survived well enough to be a century more advanced and what imagery are you talking about?

Dont forget the Midevial Era is incredibly broad and can refer to any date from the fall of Rome until the early colonial period because no one really agrees when the midevial Era ended. Don't forget Also the Aztecs and spainards aren't really comparable to the Americans and the redcoats there were a lot of reasons Aztecs weren't as effective against the spainards that span from technology,geography,politics, medically even, etc. Consider watching a video like this https://youtu.be/JEYh5WACqEk which discusses why the initial natives had no diseases to spread to the Europeans when the Europeans spread many to the natives and briefly touches on why native economies and cities were smaller due to there smaller pool of domesticated livestock. This isn't a problem I could see in ATE we aren't given the idea that any live stock are missing from America that exist here IRL we have horses, cattle, sheep, etc.

We aren't told there's been any great "reconquista" for the British we don't know if they have Ireland ore France or even Norway or any other land less than an ocean away that would have kept them well occupied I'd think or that there home islands have any better of a system where they could justify invading an ocean away rather than lands they may or may not own. They wouldn't happily cross a sea much less an ocean we have no clue if the British have the medical or logistical means to cross an ocean without massive casualties or if they even have an army that is even compensated in the way of everyone getting gold and land your making just as many assumptions as I am

Finally legendary tales, everyone has legendary tales the americanist believe the founders were God's and America is a divine land and every Christian group says that god allowed them to survive proving theyre the right one. a tale of how your better than everybody else is practically staple it doesn't make it more credible.