I want Arrowverse grouped together. However, I think the 90s Flash show and Smallville should be kept separate except for the characters from their shows that appeared in the Elseworlds Crossover (the 90s Flash TV show Barry Allen and the Smallville Green Arrow). Because yes, Arrowverse is trying to make itself even more complicated.

I don't have as strong feelings on the MCU, but I like grouping the parts that crossover, so movies as one fandom, Netflix as a second, etc, or having the whole thing under MCU.