Well, last time I played with NPCs, if you ordered them to stay in one spot they would guard that location and not require any food, water, or rest, since you probably wouldn’t be around to baby them.
As long as they’re following you, however, you’ll need to take care of them, and the AI isn’t advanced enough yet to take care of itself (find their own supplies, not fall asleep during raids). I remember they would sometimes pick up loot on their own, but it was just random as far as I remember.
There should be a mod included in the experimentals that removes NPC needs entirely since it can be such a hassle. If you don’t use that mod, I would recommend only having one or two NPCs following you around for raids. Alternatively, to ease micromanagement you could try giving your NPCs a gallon jug of clean water when they’re thirsty plus a ton of some cheap, nutritious, and low volume food that doesn’t expire. Your best options are probably granola, meat jerky, smoked meat, meat aspic, fruit leathers, and vegetable aspic.
Finally, I have no idea if this would work, but once you find an atomic coffee maker you could try having them drink atomic coffee. This would either do nothing, greatly reduce NPC sleepiness, or make things worse by preventing them from sleeping until they get a debuff from lack of sleep.
