I think the FOD/SLP/H20 should be in Fallout regardless of what you play on. hardcoe should live up to its name by having difficult choices such as only gaining health from owned beds, stims heal over time/don't heal limbs, ammo has weight etc.
Except I want it to be more realistic, say ammo, it should have more weight. A standard soldier today carries about 210 rounds for an M16. That is for standard missions, it is possible easily to double this. So I think just to make it easier you carrying weight should be decreased, and a practical amount of ammo to hold would be about 400 rounds for any to make it easy, then have your armor and weapons, then have enough weight to carry food and water.
So a character
Combat armor - 25 pounds
Combat helmet - 3 pounds
Assault Carbine - 6 pounds
10mm pistol - 3 pounds
510 rounds 5mm ammo - rounded to 15 pounds maybe
60 rounds 10mm - lets just say 5 pounds
= 57 pounds + say 10 pounds of food an water = 67 pounds. Then maybe the weight would be around 75 0 str, then str raises it by 5. So around 100 average.