What does that have to do with anything?
They are both boyscouts with little or no personality, and both refuse to take lives unless absolutely necessary.

Just because one was a soldier and one is an alien, doesnt make them different personality wise.

Are you saying that two people from different backgrounds cant have similar personality traits?

Oh, and as Cap was a soldier, then that makes a guy who plays "Captain Jack" even more likely person to play him, surely!