As we all are anticipating avengers 4, the marvel should just save themselves the stress of gathering too much superheroes. Infinity war was cool but so much superheroes for just one man and yet he still defeated them.
Imagine Marvel borrowing Superman from justice league and all their problems will be solve. Imagine having Superman, Captain America, Iron Man, Thor, Hulk and Black widow, Thanos will be a story. Lool.
Come to imagine it, it will fetch them more millions of dollars and save time, so others superheroes like Spiderman, guardians will go and finish up their own movies.
The only trick Marvel will use to pull back resurrection of all the heroes that died in INFINITY war will be the MIND STONE, we all saw it was destroyed , Thanos using time stone to reserve it back, I believe opened a portal that the survival heros will use.
Well as I said, all is my imagination.