Mobile formation flank and rear protection

[Mowgli]

I need that motorized infantry at the front though!  Most of the panzer divisions only have a single flak unit, although looks like at corps and army level there are more of those assets, 88's and so on.  I've used the towed AT gun units occasionally, although I think I remember reading that those do not have a ZOC so you can't space them out like you would with other units.

This is correct (I've tested it ingame). Towed ATGs (both in limbered and unlimbered status) do not exert a ZoC. So against a human opponent, they're not your first choice when you want to form a security cordon/cover space.

Some thoughts:

Remember that the german/us/british battalions/Abteilungen can often be split up into their individual companies. I find this very handy, but of course it does take away from your combat power up front.

The question is also what kind of enemy units you expect to disturb your flank. Against motorized units, it should be enough if you control/occupy the road net and just patrol (using a fast unit of your own) the off-road-countryside so that you have time to react with some mobile reserve if the enemy shows up. If you expect mechanized units, any clear terrain should also be overwatched/occupied. Against ordinary foot units, it should be enough to dperform some clever patroling and to keep a a mobile reserve on the road net.

Also, the effect of getting hit in the flank by minor enemy forces is not that catastrophic. As long as they don't manage to fully encircle your troops up front or box-in your supply source at the edge of the map, supply will flow "around" the enemy very easily. Even with virtual supply trucks active, your chances to pass supply tests will just decrease a little bit, unless the enemy positions several units along a main road through otherwise very difficult terrain. But I guess this might be a much bigger issue in large scenarios (I usually play smaller and medium ones).

Other than that,  I guess you just have to accept that deep thrusts lead to overextension. If a break-through can't be followed up by troops to guard the flanks (either because there are not enough troops available or the troops can't keep up with the speed of the spearhead), it gets risky. :) Don't bite off more than you can chew. Encircle the enemy sooner (a smaller part of his army), don't go to deep.

Generally speaking, I think that the problem of securing a thrust's flanks is one of the key problems and limitations in WWII warfare.

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As I've just stumbled over it, here is an extract from David Stahel's book on operation Typhoon (October 1941):

While the fallout rate of tanks was one problem Bock's armoured forces faced, it was not the only difficulty undercutting their effectiveness. Pavlov's Western Front may have effectively disintegrated, but this still left tens of thousands of armed units now operating independently in the dense forests and marshlands of Belorussia. With ever-longer German columns stretching out across the countryside, an inevitable gap opened between the panzer spearheads and the trudging infantry, leaving the vital, but poorly armed German supply columns of the "Grosstransportraum" exposed to attack, even from small bands of men without heavy weapons. As a former officer in the 3rd Panzer Division recalled:

"During the first two days of combat, unarmoured troops and rear echelons suffered considerable losses inflicted by hostile enemy troops cut off from their main bodies. They hid beside the march routes, opened fire by surprise, and could only be defeated in intense hand-to-hand combat. German troops had not previously experienced this type of war. "

Likewise, General of Infantry Gotthard Heinrici, who commanded the XXXXIII Army Corps, wrote on only the second day of the war: "All over the large fortests, in countless homesteads, sit lost soldiers who often enough shoot at us from behind." For the panzer groups the implications of an untamed rear area were immediate and profound. As they had quickly outdistanced the marching infantry divisions, a gap opened in the German area of operations through which the vulnerable motorised columns of supply trucks ran the gauntlet of marauding, bypassed Soviet units. Not surprisingly, losses spiked sharply and many vital trucks as well as their supplies were lost. An untitled memorandum sent to Army Group Centre on 3 July outlined the nature of the predicament, as well as its seriousness. The memorandum stated:

"The problem appearing from now on in its full magnitude which must be the constant worry of all responsible departments of the army group commands ... is the daily widening of the distance between the panzer groups and the [infantry] armies.

While until now this distance had relatively little effect, the early renewal of the advance be the panzer groups, with an objective more than 500km away, will have the result that 100-200-km long streches behind the panzer groups are more or less empty of German troops. That these extensive areas are traversed by the panzer troops almost entirely on the road means that everywhere there are still strong enemy elements roaming and a constant danger exists to the supply and communications of the panzer groups."

That such dangers were not heeded soon became very evident to those charged with managing the supply apparatus. Two weeks after the memorandum was sent, the quartermaster-general's diary for the 3rd Panzer Division reported:

"The supply situation does not permit a further advance to the east. The quartermaster-general's section reported this to the general [Model] and his staff; nevertheless the general ordered a further thrust eastward ... The supply route of the division is extremly bad and insecure, enemy elements in the forests on both sides of the highway."

While losses in the vital supply columns soared from bad roads and "partisan" attacks, as of the middle of the July the forward combat units of the two panzer groups were thrust into an even more serious crisis. Attempting to close a second giant pocket around Smolensk, the panzer and motorised divisions of Army Group Centre became critically overextended, while operating at their greatest distance from the supporting infantry armies.