I'm referring to this structure: http://en.wikipedia.org/wiki/Military_organization#Armies (linking to Wikipedia because the page contains stats and therefore it should be okay according to the rules).

I wonder how many armies worked on squad or even fireteam level, considering some would just charge into the enemy?

Also how did the chain look like with communist and nationalist China fighting alongside the common enemy? Did they give each other orders to attack on a certain place at a certain time?