Text Message to Thor Odinson.
Brother, I need your help.
[ a few seconds later ] Well, strictly speaking, Banner and I need your assistance.
[ immediately after that ] We need a third to assist in the take down of the invaders. And it was pointed out to me that your command of lightning would allow you to disable the mechanical ones and allow them to be dealt with much swifter.
[ a few seconds later ] And my ability to handle the Hulk on my own should things get out of hand is near to nonexistent.