When an CO/HQ stops ordering one group of units, and moves to another group, the CV is reset, so in your example it would go back to 9. However, if the command unit fails a roll, it can't order any other units.
For 1:1 level, the HQs would be company ones. Whether or not they can order other formations will depend on their tactical doctrine, which is in the lists. eg US are Normal, so can do so, but at -1; Germans are Flexible, so no penalty; Russians are Rigid, so can't.
Hope that helps!
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