Thanks for the kind words and for the question—I had a feeling this might be confusing the way I phrased it, so I'll definitely adjust for the revised version. You're correct that the intended meaning was that every scientist has to specialize in some kind of science; if you get to check two boxes, you shouldn't just take two contacts. It occurs to me now that this restriction might not even be necessary, though. Hey, maybe if you play a scientist and take two contacts, but no specialty, you're a grad student or something, and haven't picked a specialty yet. And maybe you should get to pick from page 16, considering that plenty of scientists and soldiers have had other jobs too.
I guess the short answer is that intended it the latter way you phrased it, but I welcome you to interpret it either way and let me know how it goes. 🙂