ORIGINAL: Curtis Lemay
But for the rest of the war that wouldn't be much of an issue.
No?
In March of 1942, 25 of Ausf F1s were later converted to Ausf F2s.
...Large number of [PzKpfw III] Ausf M was converted to either Sturmgeschütz III or Ausf N.
From February of 1943 to April of 1943, 100 Ausf M tanks produced by MIAG in Braunsweig (chassis numbers 77609-77708) were converted by Wegmann in Kassel to Flammpanzer - flame-thrower tanks.
And so on. Vehicles which were judged to be obsolete regularly get withdrawn from the front line and used for something else. This isn't during quiet periods, either.
But perhaps it could be addressed via a TO that would give the player with extra tanks a suite of emply tank units that could be filled with the excess. I haven't tried it, but in theory...
Well and again, in a great many campaigns both sides were supplying everything they could supply up at the front. What one needs is a mechanism whereby the maximum force is fixed- but if anything is available in excess, it's the better stuff which goes up to the units, and the old equipment gets left behind.

