Sounds fantastic! Besides, I have an "out of the box" idea and suggestion which is absolutely feasible and can be relevant to the whole game:
It will be absolutely fascinating to have a large "strategic map" that enables players to "make decisions where to fight and how to proceed to his targets" throughout the campaign.
Let me explain this further with a few examples:
Imagine you are playing with Wehrmacht, sooner or later you will historically and automatically end up fighting on two fronts (in Panzer Corps grand campaign I guess it is in 1943 that we need to make a one-off decision on which front we choose to start fighting for the whole next year and then move parts of our units to the western front and form a new second unit there).
However, in this new mode, it is practised essentially and totally in a different way.
By providing a large strategic/command map that covers the whole of Europe and North Africa, players will be able to choose where (and by which unit) to fight first or next. One may start his campaign on the eastern front (Poland for example) and the other one may begin it on the western front (Norway or Low Countries or even France, even though the latest sounds a bit crazy).
Actually, players can have at least two or three different units to fight on different fronts (East, West, Africa or all of them in one front if they fancy it) just like Panzer Corps Grand Campaign (in 1942 or 1943 where players need to build a new unit and move most of it to another front) but this time with the ability to choose which unit (out of 2-3 units a player might be permitted to form) he wants to fight with and where to fight with them, east or west or elsewhere. So he can manage to attack or defend at the same time in a large strategic map in different places with 2-3 different units.
I am sure this can be provided by your developers without a hell of difficulty as this idea, in essence, is what happens in Panzer Corps (kinda behind the scene!). Now a player can see it all in a visible bigger map and drive his forces towards his targets as he wills.
If a player's playing with Wehrmacht for instance, he can make a decision on whether to attack the Soviet Union with all his 2-3 units (depending on whether the war on the western front is over or not as well as whether he needs to have at least one strong main unit to finish it up there). He also can decide where to attack first with which units: Minsk, Leningrad or Kiev? while monitoring Soviet forces and their movement on the map. And here comes another part of this idea: instead of automatically jumping on to the next scenario based on the intelligence provided for the player (before each scenario) and practically force him to fight that specific battle, by using such a map and the same intelligence it will be his call to make a decision whether he wants to fight that scenario or not. He might want to attack somewhere else and fight another (relevant) scenario. For instance, after occupying Norway by Wehrmacht a player may want to attack Russia (hence playing Barbarossa scenario) instead of Low Country. This idea makes it possible, though it is the wrong decision as the second or thirds unit may not be as strong as it should be and finally, he will have to fight with Russians in Poland or even in German soil quite early on rather than 1944-1945 (using same maps for later stages, though with different troops based on the year it takes place). Also if he manages not to fight where your intelligence and suggestion is indicating, then he will have to probably fight it in another scenario and of course within a different circumstance. For example, after occupying Minsk your intelligence suggests the player need to attack Kiev immediately in order to outflank Russians and make them surrender, but he chooses to stay put (in a defensive position) and fight somewhere else with a different unit, say towards Leningrad or in North Africa (of course if he buys that scenario!). So as a result, he may either have to fight in a previously occupied territory (i.e. previous scenario) as it is likely he lost that area or to defend their current position or simply to face much stronger Russian forces next turn as he decides to finally move forward and attack Kiev. Also, a player may decide to attack Eygypt by landing in Palestine and not through the desert or El Alamein. So he may want to put one of the main units in Greece until he secures the sea or air to launch his amphibious attack.
Another one may make a decision only to attack the Caucasus, not in other directions (in order to cut Russian's lifeline of fuel and other supplies coming from the South, sent by Americans and Brits via Iran, and consequently affect the movement of their forces and the number of tanks, artilleries etc Russian could use, and I know this one bit is sort of tricky and maybe too complicated for Panzer Corps).
As another example, another player may decide to transfer his enormous Gustav artillery from the Eastern front to Belgium and bombard London or southern shores of England, especially when it comes to the Sea Lion scenarios in 1942 (like actual events in WWI and at some point WWII, if I am not making a mistake).
If it's Great Britain, one may decide to start his land campaign against the Reich in Africa, Normandy, Norway or even if possible in Russia to some degree! Again, all within the same scenarios already developed though with a bit of alteration in terms of slots and... In fact, there is no need for further scenarios (although the more the better!) as the battlefields and all their scenarios are still the same (it would be great to add a subsequent defensive scenario within the same maps for at least some of the major targets/scenarios; in case a player decides to stay put in his recent victory point and not progress further; so he will face a counter-attack from the enemy next turn if that place is of any importance).
This is a mechanic whereby players are able to choose where to start or continue their campaign in the long run with all their basic resources (Three basic units with different prestige depending on the country and the year they want to build them; e.g. Nazi Germany did not have the same amount of resources in 1944 as it had in 1940).
I also understand to make this feasible there might be a need to assign a certain amount of units to some potential targets and of course, not all targets can be accessible at any given time: If it is in 1942 clearly Wehrmacht cannot launch an arbitrary airborne attack to London so this can not be possible on the map (even if it was, that would be an absolute suicide mission for a unit) or in order to land in Palestine, Italian and German navy force along with their airforce need to fight with a strong British Navy unit in mediterranean sea etc, or to launch a surprise attack on Greece it cannot be possible from any direction a player fancies and...
I am aware this sounds quite imaginative and unorthodox, but nothing can be more exciting and rewarding for a player than having access to a strategic large map with the ability to see his progress and to choose how he wants to run his campaign from the beginning till the end with his 2-3 different basic units. I firmly believe it will be very interesting if you please just give it a little shot for yourselves and see how it goes.
You can have your original plan for Panzer Corpse 2 but providing such an intriguing and totally new mode (called sth like "Panzer Corps Commander") can be a significant game-changer by all means.
I REALLY hope someone in your team read this, think about it and hopefully, we can hear your opinion about this soon