I have my own theory of Avengers Infinity war parts one and two. I have a theory that spiderman would be in the team but not as the leader, but Falcon as the new Captain America like in the comics would be the leader as he teams up with Bucky Barnes the winter soldier, Scott Lang as ant-man and Jane Foster as the new Thor. For example:
If you put an all new team like the secret Avengers, you could stop evil. I mean, if someone passes the torch to his/her friend, he/she could be the new hero.
Just to say, I'm quite unsure that spiderman should lead the team.