I know a guy that was with the Rangers, but as a logistics guy. He had most of the training, but wasn't really the sharp end of the spear. He's also disabled due to getting clipped in the knee during a firefight and is considered almost fully disabled, at least from a military perspective. If someone were able to get to him before he was aware they were there (he carries), they'd have a good chance of putting him on his ass and keeping him that way (regardless of his 6'2" stature - the extra 75 or so pounds don't help, though). He looks at least five years older than me, but is two months younger. Just because you served doesn't mean you stay as sharp and fit as when you were still in, and the trauma some of those guys suffer can put them in a place physically where they can't defend themselves nearly as well as they once did, and maybe not even as well as a fit civilian with a little bit of skill.
Well said and sorry for your friend.
I was Airborne Ranger (originally signed up as 11bravo... but got hooked into and decided to be a paratrooper for the extra money)... and I jumped out of hollow metal tubes with wings and killed people for a living ('84 to '92). Despite my training, I could still get my ass kicked, particularly when out for R&R. I rotated back stateside after an incident that left me disabled while in Operation Desert Shield/Desert Storm.
Even had not not been WIA, there are always individuals that can kick your ass, if they have training, use it regularly or don't fight fairly. Just because you are a highly skilled and trained soldier doesn't mean that you are suddenly Captain America.
In the situations with the MC, frustrating as they may be, they are somewhat realistic given his current condition and that doesn't mean that he will always be that way as noted by the creator... also, the MC has a pretty good trump card... William... if there is ANYONE that should be worried about is him... I get the sense that is one individual that you WOULDN'T want to fuck with... that man not only could fuck you up, but he could probably literally erase your fucking existence.
In short, while the MC may have his hands full and sometimes get knocked down, he at least has someone powerful watching his six.