Thanks for the replies, especially your thorough response Garfunkel.
What I have been building are company sized formations of a type (INF/ARM/ART). These companies are mixed between AP, AT, and AA, with the exception of ART, which is almost all ART. I then build HQs that are literally 1 guy in a truck at the battalion (800), brigade (5500), and division levels (25k). In addition to these, I have been building supply convoys of 5000 supplies (10 trucks), and forward observer squads of 10 FOs.
My battalions are composed of this:
2 INF (300 soldiers total: 50 AA, 50 AT, 200 AP)
1 ARM (150 tanks total: 50 AT, 50 AP, 25 AA, 25 AC)
1 ART (150 soldiers total: 75 INF/ART, 25 INF, 25 INF/AA, 25 INF/AT)
1 LOG convoy (10 light armor vehicles, 500 supply each)
1 forward observer squad (10 FFD)
Does this all make sense?
Should my HQs include more than just an HQ truck?
How does field positioning affect things? Also, is rear or support more appropriate for your non-combat units like LOG and HQ? And similar for ART?
EDIT: Ohhh, good point Doren. MPs don't need fancy equip so you can churn them out!