ORIGINAL: Schmart
Also, it brings up gamey possibilities. Now the Russian player knows the Germans get to keep extra units if Warsaw falls before 1944, so he deliberately lets the Germans hold Warsaw to trigger those scheduled withdrawls... A gamey and non-historically plausible strategy.
This could be a very possible scenario if such a rule would be too simple which, is in my case, I'd base it more on certain triggers and then do a front ratio calculation closer to what the AI uses to decide whether it should be offensive or defensive (to prevent a lone russian cav unit strolling into warsaw triggering a situation where no german units are ever withdrawn). Or the other way around, what about the germans trying to force a soviet unit from the Bialystok pocket of -41 to retreat into warsaw to trigger it so he will get to keep all the SS-panzers

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A short example of how it could work in theory: The "emergency threshold" starts to be calculated when one of a set of triggers happen such as a romanian surrender prior to some date (6/43 for example) or if the russians capture warsaw say in summer 43 and so on. Once it has triggered the "threshold" is calculated as a ratio between combat units of the axis vs soviets and if the value is too scewed it would (preferebly) postpone withdrawals up until the point when the front line has stabilized, this does ofcourse not mean that the front line ratios should be equal before postponed units would withdrawn but rather just play a role up until a point when a satisfactory (semi historical) ratio have been reached.
Anyway, in essence this is a rule to cover for ahistorical cases just as there are rules written that handle ahistorical cases like Romanian/Hungarian surrender rules or the "Axis takes Leningrad so finns can assume offensive operations" rule.
As for the soviet situation it would require a different ruleset, including the "what if the germans hold both Leningrad/Moscow" case because the soviets are in an emergency from the get go on June 41. As an aside though I have played strategy games with conditional arrivals/withdrawals such as "if the germans control this/these locations on or after this date these units are released/withdrawn etc" and so on (with conditionals for some russians as well). Most of the time I believe the scenario designers (in this game) implement these cases with the use of frozen units such as transcaucasus front/italians in yugoslavia and so on.
ORIGINAL: Schmart
One thing I would like to see with the scheduled withdrawls is a bit of variability, say withdraw +/- 5 turns, or something, so that players don't necessarily know exactly when a unit is schuduled to withdraw. Another idea someone brought up a while back was having holding boxes, where a player must keep XXX value CV units, or take a VP hit, or something like that. It's a good idea to spice up the withdrawl system, but it can be so situation specific and complex that it would be difficult to replicate a robust system. And then, how does an AI control it...
The holding box is actually something I have been thinking about as well, mainly since when I play Axis I end up in a situation where I prioritize units that will not be withdrawn above those with withdrawal dates. This plays a role in many ways but for example if I have two divisions lined up for a simple attack in the early campaign (ie knowing I will win), which unit should I attack with if I have to choose? Then if one has withdrawal date and the other do not, then I will hope the morale boost goes to the unit that will remain on the mapboard over the course of the game. The same goes for withdrawal of panzer/motorized units during blizzard for example, it's like: Which units are not being withdrawn? Ok, those... Send those home to germany and the rest can spend the winter in russia.
I recognise this to be somewhat gamey as it uses knowledge I should not historically have and would probably have been better off with the example of a withdrawal box where I need to move a certain type of unit into before a specified date or just randomize the withdrawal overall as in "1 panzer division should get removed, pick one at random and do it fast!!". Point is, by knowing which exact unit is to be withdrawn and when, I have knowledge that my counterpart in history did not have and I can use and abuse that knowledge in several ways. Another example being the reduction of max TOE% 6 turns before withdrawal dates or the commitment of units that are to be withdrawn in "banzai" like kamikaze attacks, the Italians in 1943 followed Bushido, didn't they? Mine do anyway... [;)]