Scans_Daily

In theory, the Illuminati is not just a good idea, it's an essential idea.
Of course the X-Men, Avengers, and Fantastic Four should trade notes. Someone needs to speak for the mutants, you need an expert on magic, you need an expert on science, and yeah, it doesn't hurt to have people like Namor, T'Challa, and Black Bolt to represent powerful nations/sub-sets of superhuman races.

But it should have been an above-board council, not a secretive cabal. There should have been some form of accountability and continuity--someone retires, dies, goes away, you get a replacement. And when there's a crisis, you don't set these schmucks, you get an appropriate team to handle it.

The problem is that you had too many kings, all jockeying for position, with clashing egos, and no one to rein them in diplomatically. And when things went sour, no one was able to stop it before it went pear-shaped and nations went to war.

The best way for this to work would have been to include Captain America for tactics, leadership, diplomacy, and mutual respect... and Spider-Man for moral compass and because he's one of the very few heroes who A) works with EVERYONE and B) Is friendly with but not beholden to any one team most of the time... Oh, and maybe actually have a female member like Sue Storm or Janet van Dyne to offset the testosterone. (I'd have suggested Carol, but she's been off-grid a lot during her career.) Maybe Jen Walters, for her legal expertise and common sense.

In fact, yes. Here's the set-up I see as being best for a saner version of this group:
Xavier to represent X-Men and mutants in general. Backup: Storm.
Reed for the FF and for Science! Backup: Sue.
Tony for the Avengers and again, Science! Backup: Janet.
Steve for the Avengers and general cat-herding. Backup: Sam Wilson?
Stephen Strange for magic. Backup: Shaman (or Brother Voodoo)
Black Bolt for the Inhumans. Backup: Medusa
Namor for the Atlanteans and oceanic expertise. Backup: Namora?
T'Challa for Wakanda, etc. Backup: Um... Shuri?
Peter Parker for unaligned heroes, moral compass, etc. Backup: Ben Grimm.
Jennifer Walters for legal expertise. Backup: Matt Murdock.

As needed:
Carol or Rhodey to act as military liaisons.
Thor or Hercules to act as mythological liaisons.
Natasha or Bobbi to act as SHIELD liaisons.

This would not be a Secret Avengers/Illuminati set-up. no. But I'd sure have fun reading it. :)