What he's primarily known for is as a living symbol of the American Dream
*facepalm* Oh my god, that's his character concept, not - holy crap, you have already stated you consider Misty Knight a martial artist, and you also stated she used her martial arts after she runs out of bullets! By your standard Psylocke is not a martial artist, because she was primarily a telepath/telekinetic, and she's a ninja assasin! Daredevil isn't, because he is primarily known as Scary Devil Guy And Possibly Blind Lawyer With Many Dead Girlfriends! and he's HEAD of a society of ninja assassin!
overwhelming defined by popular concensus as fighting styles coming out of Asia
Well, okay, if you want to go by pop-culture definition instead of the actual definition, Cap's two primary fighting styles are boxing and Judo. Judo is Japanese, so even by your standards, he's a martial artist, even if he also throws a big chunk of metal about in a non-deadly fashion. (Like a super-sized shuriken! He's practically a ninja.)