Well that's kind of what I figured, but I just had to ask ^^
Awesome posters btw. All of 'em. And I actually think the radiation sign for the Hulk was a great choice, people seem to be forgetting that the Hulk was not only created through radiation, but that Bruce Banner is also a radiation expert, it's his main field of study, making it entirely appropriate to have a radiation symbol as his sign
Do you think radiation sign is the best for The Hulk? I mean - yes, a gamma-radiation burst made Bruce Banner what he is now, but - could it be something more greeny-fleshy? Like his strong green hand or a fist.
Everything else is well done, although those of us who haven't yet read Avengers comics won't recognize the mask as Hawkeye's symbol.