I'm less familiar with Uncle Tom in actual usage, but isn't Chad usually a positive thing? Like flattery? I think I'm okay with positive sexism. I also don't know what Stan means.
Chad isn’t positive, Stan is an obsessive fan. All these terms criticize the behavior that happens to correlate more with the sex/specific identifying factors, it’s not because of the sex the behavior happens.
Uncle Tom is more of a black on black insult. Very serious insult at that. It has somewhat of a racial undertone of a black person being a brainwashed white suck up so it's not thrown around lightly. Some believe the use uncle Tom is done incorrectly but it's to big now.
Chad is definitely not used positively in my experience. I know some people in the MGTOW / Pickup Artist community they use it in a positive manner, but everywhere else basically a Chad is an overly aggressive up his own ass douchebag who thinks he is an alpha male, etc.
It's funny I always used to think "hot take" meant informed opinion but after reading this thread and looking up what it actually means, I sound just as ignorant as you.
Chad is positive only relatively recently. The name's usage in the vs virgin memes was originally meant to be ironic. Like you might hate the Chad, and the meme assumed you would, but the funny part of the meme was that the Chad is still happier than you.