[Tris]

You couldn't stop the big force by throwing individual commanders at it. Given that the armies have a chance of meeting based on size you'd need at least a certain size of army to have a decent chance of meeting the big army.

This would mean to quickly move large armies against such skirmishers you would need faster strategic units to intercept the skirmish bands, and push them back ahead of the main army.

The main army would be unable to break camp and march significant distances, as they would be forced to deploy for battle against the hit and fade attacks, unless you had countered those attacks with a light force of your own.