The Blood War is the Big Planar War between Demons and Devils (The angels get involved sometimes, too.) The point I was making is that the Blood War is one of the few places where that ranking schema for characters of that level would be appropriate.
Like I said - I'm not saying it can't work. I'm just saying that a level 12 character is the equivalent of anything from a couple of squads to a sizeable portion of an army, depending on who and what they are. Having them all be in one squad represents a significant investment of strength - having them all be that low in rank looks really, really strange.
Let me put it this way - in bog standard D&D, a person with 1-2 levels in *any* PC class would probably qualify as an NCO. Anyone higher than that is getting into officer/specialist territory. And given that full spellcasters power up on a geometric curve...
This is doubly true given that we're all evil or neutral - if everyone in the command structure is higher level than us, why have we not conquered the city yet? If they aren't, why haven't we, uh "promoted" ourselves? And if level 12 really *is* suitable level for infantry grunts in this world, does that mean the baseline for power is that high? Because that's pretty terrifying. It means we've got hobos with the power of archmagi running around, and anyone of significant power is well into epic levels.
Like I said, the Malazan Book of the Fallen is partially built on just such a conceit. I'm just wondering what the reason is.