I can see it working.
Ant Man is a bit of a silly character. It's hard to play it straight. So you can a comedic action with the acting chops and standard movie star looks to make the serious action movements works but the goofiness to hang a lampshade on the fact he's choosing to shrink to smaller than a centimetre to fight crime.
Plus the big Ant Man story was always To Steal an Ant Man, which rumours have as the story they're adapting. (Which skirts the issue of making a movie about a dude most famous for smacking his girlfriend.)
Which would make Rudd
Scott Lang not
Hank Pym. And Lang is not a serious person.