I thought that battalions were the main tactical units, usually operating together on the battlefield. The way this game is built, and especially its custom battle function, it rarely gives you enough points for a full battalion, if you want additional support. Iím not a real world soldier, I donít know what the practice is, but isnít it a bit unrealistic to have a battalion HQ with just one or two companies?
It is very possible to play with an entire battalion. Some players prefer this. It is often possible, in Quick Battles, using the point system and selecting a Huge Battle. Or the editor can be used to modify an existing QB or scenario. Some scenarios have been designed with more than a battalion.
Having said all that, many consider a reinforced company sized engagement the sweet spot for Combat Mission. This is because the player must issue orders to all the friendly squads and vehicles on the map. This can be a lot of orders if you have an attack mission and open the map to see an entire infantry battalion waiting for your orders. However it is very possible and some players enjoy commanding battalions.
Combat Mission allows the player to command everything from a fire team or vehicle up to a battalion plus. The scenarios and Quick Battles reflect this. The mission might be to command an infantry platoon and recon a village or command a mechanized company to secure a bridge, or use an unconventional combatant group equipped with IEDs and VBIEDs to ambush a convoy etc.
As in real life all commands in a unit are assigned their part of the mission. The squads mission is to take the farm house, so the platoon can secure the crossroads, so the company can take the ridgeline so the battalion can secure the town so the brigade can........ etc.
By choosing the scenario or Quick Battle (or using the editor to create a scenario/campaign) the player can choose his level of command (up to about a Bn. plus) and TOE.
It is useful to have the Bn HQ on the map if there is more than one company to facilitate Combat Missions C2 system. Alpha Company reports up to Bn. HQ. The spotting contacts are then disseminated from Bn HQ to Bravo Company via the C2 system. No borg spotting in Combat Mission.
Below is a link to how the C2 system works. The screenshots in the link are from a WW2 title but basic C2 system is the same.