Not sure if this is exactly what you're looking for, but I've houseruled something similar--though designed with LT settings in mind--in a thread called
Big Fights and Long Fights in GURPS. This would be the Long Fights part of the problem I addressed there.
The solution I tried to make was something that was a stylistic compromise between GURPS tactical fights and the large resolution of Mass Combat. The squad mechanics could be worked in more easily this way, since the rolls are more infrequent and cover longer periods of time.
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Finds party's farmboy-helper about to skewer the captive brigand who attacked his sister.
"I don't think I'm morally obligated to stop this..."
Ten Green Gem Vine--Warrior-poet, bane of highwaymen