So, how is that career situation going to be different from OTL and going to affect the US military?
All I have is a vague impression that OTL, special forces are considered gold plated.
OTL special forces don't really become prominent until Gulf War 2.
Prior to that it's basically 'weird guys who do weird shit that are probably war crimes if we think about it too hard'. Like the Spetsnaz doctrine is literally classified as 'unorthodox' or 'special' operations. Meaning, outside the norm.
However, with the simple fact that the US was utterly terrible at pacifying (and that's the polite term for colonising) Afghanistan and Iraq for 20 years, special forces become more and more prominent. Like, putting it another way. If you aren't going to be obliterating entire villages with artillery and instead trying to use surgical strikes to remove an enemy from the field, you cannot use regular infantry because standard doctrine says 'bomb them to bits with airstrikes, then tanks, then the infantry move in'. Which is a good way to make many enemies indeed.
Not that it worked very much with the actual doctrine that was implemented. But that's not really the point.
The point is that the soldiers being sidelined in offensive operations due to the indiscriminate nature of, well, a thousand guys with guns, you see special forces take up position as the offensive spear of the military.
In doing so they become massive, with an entire command structure in place for all the different special forces to be seconded under (spec ops command) so they can be coordinated more easily. I.e. SEALs, Delta, Green Berets, MARSOC, etc, all come under one unified command.
These guys are the ones raiding villages for leaders, shooting up the bad guys in daring helicopter raids, etc.
And since they're the ones actually
doing something that everyone thinks 'matters' (because being on the offensive means you're winning right?) in the field, they become the focus of the media and a bajillion films, books, comics, documentaries, and games are made about them. Combine this with the fact that, well, you're fighting peasant farmers with WW1 vintage rifles... these guys tend not to die as much as their previous counterparts did.
It's super glorious, super interesting, and everyone is happy to go 'these guys are awesome'.
But here's the kicker.
In a conventional war, these guys die like flies. Look at the survival rate of Commandos (British and otherwise) during WW2. Something like 50% iirc were injured, 30% died. Not even including those who wash out during training due to injuries or other issues. It is supremely dangerous, you're going behind enemy lines as
light infantry, trying to sabotage enemy forces/infrastructure for the benefit of the regular forces on the ground. If you are found,
you die. You literally have a rifle, a grenade launcher, maybe some explosives against tanks, planes, helicopters, etc.
Which means that you need to operate on a completely different paradigm from regular soldiers.
So when they're looking at promotions, you need to consider exactly what these people bring. Someone who thinks in terms of surgical insertion of operatives into a hostile environment might be good for a general of special operations, but how exactly is that going to help when you're commanding an Army Corp made of cooks, engineers, drivers, soldiers, tankers, etc. With Special Forces being outside of your control entirely?
They don't have the mindset of being regular infantry, of which the vast majority of the military is. So they can't effectively command regular troops,
because they aren't regular troops.
It's why special forces are treated as their own special community, because they are one. A bit of a divergence here, but the Latter Day Saints in the US are heavily recruited by the Special Forces. Why? Because they have an aversion to tattoos, huddle in their own communities (good opsec), and are very American indeed. Which means you get father/son, uncle/nephew recruitments into certain units due to how long the war on terror lasted (like CIA operations where secrecy is important). It's a very insular community.
These people don't do well as leaders of the regular army.
So when you're looking army leadership, special forces don't show up.
That being said, the line does blur.
10th Mountain (OTL is basically 'slightly' special, but really are the same as everyone else no matter how much they say they're special), the Rangers, 101st Airborne, etc,
technically can be called special forces, but really aren't. They're just really good light infantry, that get seconded to special operations every now and again. The Rangers complaining vocally about this role given they play blocking forces for the SEALs, Green Berets, etc. Which is basically light infantry vs light infantry as the insurgents try to escape, which causes disproportionate casualties on their part.
In the US army especially, if you don't have a Ranger patch (went through training, didn't need to deploy), it's going to be weighed against you when applying for a combat posting... which is super necessary if you want to get the merits on your profile for further promotion.
So being in these units isn't a mark against you. Being the 'operator' units is however.
So, cutting a very long, and long winded and probably useless post short.
tl;dr, SF won't be considered for army leadership in OTL because they are trained differently, fight differently, form their own insular communities, and thus think differently from the rest of the military. Putting one in charge will cause massive issues, thus they don't get promoted past a certain rank to prevent these issues arising.
