Well depending on how well it worked for the gameplay, that suspension of disbelief might come a lot easier. Here is the reason I find it intriguing…
If for example, you were to get 1 free infantry mobilized in a place like Hawaii, the player would have a strong incentive to develop a permanent logistics operation there, which would activate the whole area around the territory each turn. You’d want to have a transport at the ready for example, and some warships or fighters to cover it. Likewise, as an opponent, you’d be keeping an eye on that territory as well, and want to contest it.
I grant that it’s not quite as flexible in the abstract as say a National Objective bonus of X ipcs, but by restricting it to just infantry, I think some abstraction here is certainly possible.
I would suggest not trying to be too specific in the description of what exactly the infantry represents. Keep it very broad. Let’s say for example that it could represent not just local recruits, conscripts, partisans or whatever, but normal occupation forces or defensive garrisons or expeditionary troops awaiting deployment on a regular basis. Or if none of that works exactly, then don’t even get that specific. It’s not a very radical departure from other things that happen in game.
The point I was making is that this rule would make each VC important for all nations every round, and it’s very simple to implement. Much easier than even an equivalent cash bonus would be.
I honestly think it would be simpler, if it just used the China spawn model, because that provides an immediate incentive for the attacker every turn (as we see working in China OOB). Holding the territory for an entire round is much more challenging, I think in this case the double dip might actually benefit the gameplay.
But if that is too much for you, then controlled from the start of the turn would work as well, and wouldn’t be too hard to track. Again I would try to avoid making the analogy too clear or too one dimensional, as to what the inf is representing exactly, instead leave it as open as possible (broad strokes) for whatever interpretation makes the most sense for any given territory.
I don’t see a need for this rule to be attached to others to function. It would work all by itself. And I think it would work on all boards that have VCS. Though of course if it works as a stand alone, it would likely work with others as well.
I think what it offers to the gameplay goes well beyond a desire to have Marines in global, or improve bases or ships etc. It could fix the Victory condition problems for all the recent maps.
So I would not rephrase the rule to try and accommodate other HRs or connect it into some more complicated system. That stuff is unnecessary in my view, because it functions as a stand alone the way it reads now, and offers a lot with very little overhead in the implementation.
I’m not hugely invested in a 4 part rules change to the global map (that stuff is great for those who want to pursue a more sweeping HR change to G40), but a single rules change for all maps since revised that fixes the VCS system via one universal mechanism is very attractive. It would be very easy explain and very easy to test.