I’d rather a guy with a grunt background, mindset and experience cross over to a non-infantry MOS. Going into a supply or commo background with knowledge of what the guys getting it in need is a far better situation than some guy who isn’t a natural born killer coming into the infantry, with the mindset of someone who was supply and is too worried about the admin side of the house and risk mitigation, than they are on turning their boys into savages.
Non-USMC related but look at the issues presented in “Relentless Strike” with the aviators who ran JSOC at the beginning of the war. Dell Dailey ran an organization of meat eaters with the zero-defect, zero-risk mentality of an aviator, and what do you end up with? “A Ferrari stuck in the garage.”
If anything they should be attempting the reverse of this proposal- everyone starts as an Infantryman and then can move into a non-combat MOS after they have the experience.