I wonder if the size changers were purposely left out because they weren't confident in their ability to show the size change on film? Does anyone know of other live action movies where they've successfully shrank or grown a character? I'm sure there are examples, but none come to mind.
I could honestly do without the Panther. He doesn't bring much to the table in terms of powers, so with somewhat unpowered characters in Widow, Cap, and Hawk, I'm not sure what he adds to the table. Same story with Swordsman, Mockingbird, Tigra, or other low powered characters. I would definitely like to see the size changers come on board, and they could easily build a plot around Wonderman, Black Knight, or War Machine coming on board. Even Scarlet Witch and Quicksilver would be nice additions. I'd think they have to include another woman or two on the team - it's a bit lopsided with just the Widow, especially when you compare to what they've done with X-Men (Storm, Jean, Mystique, White Queen, Rogue). Maybe we'll see Ms Marvel or She-Hulk strut their stuff in the sequels.
