Hmmm, I think these are really good points! I do think the basic "stays up for 3 days trying to save somebody/fix a problem" issue is something that just about any really driven character could do - e.g. Peggy not sleeping because she's trying to, say, find Daniel or something. But it'd have to be something really dire. As opposed to just something that people like Tony or Rodney might do as a matter of course. (Although, do they actually do it in canon? I guess there's that one time when Rodney and the other scientists are taking stimulants because the city is literally about to be wiped out by Wraith, which I think is where a lot of the "Rodney stays up for 72 hours straight and starts hallucinating" fanon comes from, but that's also a situation in which the military would most likely end up in the same condition too. idk.)

Anyway, I do think it's true that it just "feels" right for characters like Rodney or Tony to do this, where it doesn't "feel" right in the same way for someone like Peggy. I don't really have a better explanation though, because when I think about it I can totally see Peggy pushing past her physical limits like that -- I mean! She does it in canon, with say, going to the fundraiser when she's suffering from an abdominal wound. But with just staying up for days trying to solve a case, it doesn't fit in quite the same way. I think you're right that she'd take naps or something because she doesn't feel like she has to be "on" all the time.

I also really like the idea of Jack working so hard to maintain the facade that he works himself into a state of collapse. :D