Need help with military units for my novel . [ OT ]

http: //en.wikipedia.org/wiki/Military_organization 
 This has some really good detail. Also, the units you will want to use will depend on the point of views expressed in the book. If, say, the perspective is that of a commanding officer in a Russian force, they might have the same organizational system but different words ( because they speak different languages ). Now, because you're looking for units for Heaven and Hell's forces, their is a chance that the language barrier is irrelevant. If your prospective is from someone omniscient ( god, a narrator, etc. ) then the units will only serve as good synonyms to avoid rereading the same term over and over. If that's the case, I would go with roman military units, as the rise of Catholicism went hand in hand with the Roman Empire. 
 You can keep it fresh without much effort if you're jumping around from perspective to perspective, but remember that a Egyptian commander might need a translation/conversion of how many units of his smallest force equates to the size of the enemies' ( a rudimentary example of a problem I'd overlooked when I was writing a war story ). 

