re: Has Marvel ever missed the mark regarding casting?

I'd say casting Natalie Portman was a bad choice. Any time one of these franchises tries to go for that "Oscar winning" person I feel they are a bad fit. (ie Jennifer Lawrence as Mystique). This is the main reason I'm concerned about Brie Larson. But it at least seems that Brie really wants to do this character right rather than just phoning it in. Time will tell