Complete lack of military logistics

You'd think that every firefight has absolutely no support lines, no medics, no one running wounded men to the back, no supply depots, no radiomen, no chain of command giving orders, no briefings, no relief rotations, no watch schedule, no ammo runners, no one running between units to coordinate, no wounded marines being cycled back to the beach, nothing. Is that really how it was? Surely that's impossible. The intention is probably to make it look like a clusterfuck but it's just silly. It seems insulting to the men that made the entire infrastructure of war and V-J Day possible.

In reality over 17k armed forced were medevac'd from Iwo Jima alone, yet in the episode every casualty is treated as a fatality and zero time is given to any form of medical assistance or coordination whatsoever.