You could, that's why it makes no sense to me. If you take 1 trait of Captain America and give it to each of the other Avengers he's also rendered a ghost. If you take 1 trait of Legolas and give it to each of the other members of the LotR party, you don't need Legolas at all. But that's not how it works.
It's not even cocaine mixture or anything. It's just chrome spray. It gives them no adrenaline outside of the fact these guys are so conditioned to believe in Valhalla that they pump themselves up just to die worthy in battle. It's kinda like putting two coins on a corpse's eyes for the boatman of the river Styx. It's just mythology ("You shall ride eternally, shiny and chrome").
They had a doctor on the squad (the Organic Mechanic), he's the guy that was tattooing Max' medical information on his back and also the guy who did the C-section on Angharad.
Nux wasn't, in the scene where the War Boys prepare to go after Furiosa you can see other war boys hooked up to bloodbags beside him.
The small guy was one of Immortan Joe's sons, he literally tells Rictus (the big manchild, also a son) to check up on pops when they realize Furiosa has gone off-road.
The guy with the fat feet and ankles (it was only one foot actually) was The People Eater, the Mayor of Gas Town, the place Furiosa was supposed to get supplies to and from, similar to how the Bullet Farmer ran the Bullet Farm and Immortan Joe ran the Citadel.
It is make-up. The War Boys are Immortan Joe's troops (battle fodder, as Angharad calls them) and a class below the Imperators (that's why none of the War Boys on Furiosa's rig questioned her decision to go off-road).
There are buildings and roads but since the cities were total chaos a lot of people went out to drift the wastelands. So they're literally in the desert and there ain't too many buildings and roads there (obviously there's a clear road from the Citadel to the Gas Town as we see Furiosa take it).
