Very interesting idea to have a set group on call to deal with specific threats.
It seems, in many ways, to be the reverse of what we've seen so often - heroes having plans in mind to take down other heroes (really highlighted with Batman's plans in the Tower of Babel storyline).
I can't think of many (if any) examples of a preplanned strategy to deal with a threat like Thanos or Ultron. Perhaps there are some "Galactus Protocols" in place but I'm really not sure.
WOuldn't it make sense for someone like Tony to spearhead something like this? Not a full on proactive approach (such as the Ultimates who are trying to deal with problems before they arise) but a prepared reactive approach?
If anything, such ideas get thrown out once, and then quickly forgotten the next time the baddie shows up. We had the Magneto Protocols, but they're never used for some reason.
Galactus Protocols were a thing in Black Panther, once.