Mobile formation flank and rear protection
In the Smolensk 41 GC, I'm running into the classic problem of guarding flanks and supply lines as my mobile formations break through and move eastward. So far I've followed the Germans' historical method of doing this, by leaving light covering groups to contain known enemy areas of concentration that are being bypassed. I keep light units (recon, engineers) on flanks and behind if I know there is a possibility of some bypassed enemy showing up and harassing my supply trucks. I'm wondering though if I'm "doing it right".
Looking at German situation maps from this time you will see a lot of on-map VA's, security detachments and the like guarding bridges etc. But it isn't clear from the histories what these VA's were composed of. In the case of Panzer Group 2, even Guderian says that two battle groups were created -- "Streich" and "Usinger" -- and used as covering formations around the western side of the Soviet "Orsha bridgehead" while 47. PzK bypassed it to the south. But he never says what assets were used to construct these formations.
I like to use recon units as much as possible for their intended purpose, as advance party for a mobile division's main body. So I end up using corps assets here and there to cover rear lines, usually engineers. But ideally I could have these up closer to the front too, so I can put them to use in assaults.
Sort of a rambling question, but I'm mostly curious what other folks do to address this problem. Thanks in advance!