Only a fraction of military assignments are combat positions. I knew one Viet Nam vet that spent his entire tour in an air conditioned bunker in Saigon hanging tapes on the computer that printed payroll checks.

Another, technically in a combat role, spent his tours in the radio room of navy destroyers banging out Morse code.

The problems you list are mostly surmountable.

Someone who enters the military goes through military training. If we're just forcing people to work, it's not military service. It's slavery.