Dissected your post:

Quote Originally Posted by Blatta Optima Maxima View Post
A unit is defined by its purpose, not the details of its operation and strength.

So units are neither about their numbers, or the way they are arrayed on the battlefield. What the hell are they defined by, then? The answer couldn't be simpler - their role.

the distinction between units primarily administrative and primarily tactical

Larger units formed in a generally ad hoc manner.

Cool story bro.

What do you want to discuss?