Shepard was elite special forces, top of the heap. But so was Anderson. And possibly the Big Dude from ME3. The only thing they have in common is that they went on covert missions. Is that the defining characteristic of special forces operatives? Shepard gives the impression of working loosely with the command structure, but that's more being a Spectre than being an SFO.
Special forces in modern American parlance is a guy who gets to do action-adventure style missions. That can't be correct (or at least not the whole story), it's just an easy word to throw onto something so the author doesn't need to worry about actual military command structure. Which leves me up a creek as far as wanting to know how it actually works.
Shepard I can buy being in the top 1/7th o the special forces. Anderson too, even, considering that he was one of the first to receive such training and designation, and because he's a closet Bad 'orse. But beefy squad member? Noooot so much. Which may be why he failed the N7 trials now that I think about it.
Zevox: consider a counterintuitive caster. Try Turian soldier, with concussive shot, proxy mine and incendiary ammo. You'll get just as many bursts, stronger ones even, have more general health and increase damage from all sources to a target by 20%, including primer, detonator, burst, DoT, and carrying fire. Concussive shr tears banshees and collectors to bits, proxy mine damages everything, able to drop a platinum hunter or pyro in 1.7 uses, and was the difference in perspective between gold being hard and platinum being like a tough silver match.
I just ran through a platinum match as a vorcha soldier, a terrible idea. We got to wave nine and croaked, because two of the guys who agreed to our strategy took wide liberty with it and broke class/power usage/movement/priority/role implementation. And we still pulle up to nine by virtue of just two guys coordinating. I'm frequently out of medigel, so that's not what keeps me alive. I rely on flamer, so it's not the weapons or powers. I don't melee, and my regen was pretty crap. It's coordination. You're not goin to die coordination without a mic below gold. Especially not with people playing bad class/weapon/level ominous for challenge points.