As others have certainly hit on, at this scale flanking is far more a result of deployment and orientation resulting in mismatch than it is something as simple as “we attacked from two sides”. If nothing else, the range of direct fire weapons is only going to be mutually supporting near the seams… let’s look at a few examples of how this could be a coding nightmare:
1. You have a unit holding the neck of a penetration. Let’s imagine it’s commander has a nice conservative one regiment facing north, one facing south, a central reserve and the division guns and trains between, and is tied in to friendly troops along the front, meaning his east and west are “empty”. How do we program that not only visibly, but with an AI that can reach to in turn developments to prevent wild gaming of facings at odds with the scale? And to prevent a death by a million clicks or orienting tony bits of force structure?
If you attack with three divisions from the north, they strike one regiment which gets reinforced by the reserve, creating a 9:2 or so and then dislocating all the support and forcing the southern regiment to flee. Attack two on one side and one on the other and you get 3:1 odds effectively deployed. And that’s if you don’t screw up the timing. Here flanking was probably actively detrimental. Can I program it to show that flanking at the level in question is many times going to end up creating a broad and more even engagement rather than a victory against a narrow point, while in others it meets no resistance?
But if the reserve marches to the wrong side, flanking is positive again. Invisible leader checks? But if you mess up the timing, you actually get attacks defeated in detail? Massive increase to the split HQ malus while flanking, but only if the internal arrangement of the target would penalize it? More leader checks? Where do you record this? What happens when the “realistic” answer might be the side with a river can hold later, so maybe a good commander would crush the non-river side attack and then turn all but a tiny force to slaughter the river crossing in turn? And if players disagree with the micro-tactics involved?
2. A plain old piece of the line, two up one back. When should it transition to a “neck” upon hearing a tank corps broke through forty miles north? Triggered to MP of the pen unit? Lots of super game manipulation going to happen there, and completely below the level of stavka/okh ability to even perceive. When hexes turn? But wouldn’t that make you impossible to flank of the AI auto redeployed to counter each time? Can it only redeploy of not in Zoc? Is that one airborne brigade really keeping mannstein from noticing the onrushing tank army and keeping his divisions facing “forward?”. Can’t at all? So those FJs have been listening to reports of Russians coming down the line for half a week, and no one thought to turn?
3. A fortress coty conducting a 360 degree defense by nature with interior lines falling back on a river port. Hoo boy, try that one on.
As Boyd would tell us, flanks at this level are simply directions from which we are unprepared to receive an attack, and by nature fleeting and transitive, opportunities found and taken or lost in the moment, far more reflective of initiative and surprise than any set geometry. If you can program that…hats off.
And there is the mega elephant in the room - after all that effort, would we substantially change the battle or campaign outcomes? Or would it all even out to something represented by a few numbers like NM and leader skills?