I've sperged on the "core/A-list" set of solo heroes/teams of DC and Marvel before precisely because of this, because even wise adaptions of the DCU/Marvel U in general still need to start small with only the most important characters. And even then I think the Big Two comics' universes themselves tend to lose track of this thought, lavishing too much attention on something new when keeping their core well-fed with stories, villains, or creators is far more important. Like for DC it's Supes/Bats/Wondy/Flash/Lantern and JLA/Titans, Marvel's Spidey/Cap/Iron Man/Thor/Hulk and FF/X-Men, yeah? Five solo books and two team books would be a lot for new readers to splurge into.
Ultimate Marvel to its credit did only have four titles to keep up with no matter how overstuffed they could be in the actual stories, which is IMO what helped make it so successful besides the then-freshness of the storylines inside. Return to those specific titles (Spidey, Avengers, X-Men, FF) in a Neo-Ultimate Marvel and for an Ultimate DC just make it.... Supes, Bats, Wondy solo books and a JL book featuring the rest of the League, maybe a Titans book if you want but Dick Grayson more prominent but he can safely be a regular in Bats' book. Four titles each.
For DC it's really
Supes-Bats-Wondy-Flash-GL+ JLA/Titans. Then after those, it's some mixture of Aquaman/Plastic Man/Famous JLA-Titans Members/JSA. DC's still pretty Silver Age centric at times, but literally every relevant hero falls under the JLA-Titans-JSA tree anyways except for Doom Patrol (aside from Beast Boy).
for Marvel
Silver Age mainstays in general, honestly. Were they a mainstay in the first decade of marvel? Then they're all part of the core introduction of any marvel property being adapted, usually. Otherwise we get into the usual shenanigans. Add the Bronze Age/TV show X-Men lineup to whatever X-Men property is being adapted, on top of classic X-Villains like Apocalypse and Mojo. War Machine/Falcon/Luke Cage/Danny Rand get added to the Marvel world's background in some manner. Need more "street" heroes? Cloak and Dagger are often added. Also toss in Ghost Rider or Blade as needed.
Ultimate DC could honestly worth with Supes/Bats/Wondy/JLA book with a sorta anthology title to get Flash/Lantern/Dr. Fate/etc. established
You had to remind me how aggravating the wait for Ultimates 1 and 2 were. A joke at the time ran that we got more Ultimates animated movies than we did issues one year. And the Ultimates were frequently guest-starring in Spidey and X-Men and used for a couple crossover mini-series like Ultimate Power (did I remember the name right?) precisely to keep them in the comic-buyers' eye because of Hitch's (lack of) work ethic.
I don't even remember Hitch that well lmao.
Ultimates was a cool idea that just felt like it got bungled. I'd be glad to see it restarted and just have Miles go byebye.
The animated Ultimates cartoon movies. Oh man. I think that's how I experienced Black Panther for the first time.
Anyways, another point I have with the bloated universes of DC/Marvel is that every time they try to trim and prune them down, they often wind up not doing it all that well. I think Marvel hasn't had any major issues aside from trying to insert Ultimate Universe characters into mainline marvel, then not using them aside from Miles/The Maker.
DC did a decent job with the original crisis. My issue is that Infinite Crisis/Final Crisis didn't see any real use of the Multiverse. I think we had like 2-3 little story arcs in the JSA/JLA books in the mid-late 00s that used the Multiverse a little, but it wasn't much.
If you're gonna bring this shit back, at least use it. Countdown was garbage. Final Crisis was a bit of a schizo mess with all the tie-in miniseries. It felt like we shoulda had a few years of "wonder" with the Multiverse. Maybe have someone show up trying to manipulate situations in the background with multiversal resources. You're telling me we had a JSA arc involving a time rewrite into the Nazis winning and we didn't have Overman show up?
I'm just convinced that DC's powers that be have been drinking the retard juice since 1990.