I was trained as a medic, and one thing our officers repeated time and time again, was that "I'm a medic, shooting people is not my job like with regular infantrymen" is never a good excuse for anything. I do the exact same mine-placing, ditch-digging, shelter-building and shooting as the combat engineers that I'm grouped up with. I may not do them as well, but I'm part of that same team and I will contribute, even if in a field where I'm not as adept in.
It also goes the other way around, as all infantrymen have to be able to do basic first aid
Versatility is as important, if not more so than specialization