It's a completely flawed comparison. Hitler was capable of making coherent sentences, and he was doing it rather well. He wasn't just identifying a few catch phrases (build a wall! Lock her up!) and repeating them ad infinitum to make the crowds go wild.
Fascism doesn't need to look like a bunch of drooling idiots in adult diapers. That's just the specific branch of it that ended up successful in contemporary America, for whatever reason.
If he made better speeches I don't think his base would be capable of following him. He's the perfect authoritarian for the people he's leading, as illustrated by the failure of the Republican party to find a substitute for him.
DeSantis is more cognizant, and happy to ape anything Trump does to get a following. He's a total failure.
Trump's lack of coherence makes it possible for him to get away with literally anything, as you can always chose what you want to hear and what you want to see, and there's always something he has said that indicates he feels exactly the way you do about things. It's a talent that is, thankfully, not easily imitated.