Bear in mind that the Möbelwagen was a stopgap vehicle and the Wirbelwind and Ostwind both went into production in 1944, when German tank production had to compete with said Königstigers and other idiotic, resource intensive wastes of factory production.
I could definitely see most of the Flakpanzer IV concepts going into mass-production if times were different, and that's a big part of HoI IV.
Flakpanzer 38t (1 x 2cm Flak) - 141 constructed
Mobelwagon (1 x 3.7cm Flak) - 240 constructed
Wirbelwind (4 x 2cm Flak) - max 105 constructed
Ostwind (1 x 3.7cm Flak) - 44 constructed
Kugelblitz (2 x 3cm Flak) - 5 constructed
SdKfz 6/2 (1 x 3.7cm Flak) - ?
SdKfz 7/1 (4 x 2cm Flak) - 750+ constructed
SdKfz 7/2 (1 x 3.7cm Flak) - 1000+ constructed
SdKfz 10/4 & 10/5 (1 x 2cm Flak) - ?
SdKfz 251/17 (1 x 2cm Flak) - 200+ constructed
sWS (1 x 3.7cm Flak) - ?
That's less than 550 German SP AA on tank chassis compared to at the very least 2000 on half track chassis. Then there's many thousands more AA guns towed by half tracks. As the options in game look to be horse towed or SP, those thousands of vehicle towed AA guns would also need to be constructed as AA on tank chassis by players.
Looking at the SP AA of other nations, I'm seeing many guns mounted on half tracks and trucks. For tank chassis, there's the Soviet T-90 (2 x 12.7mm) prototype, Japanese Type 98 (2 x 20mm) cancelled in development, British Centaur AA (2 x 20mm) 95 produced, British Crusader AA (1 x 40mm or 2 x 20mm) limited use, Soviet ZSU-37 (1 x 37mm) 75 built after the war, Hungarian Nimrod (1 x 40mm) 141 produced, US M19 (2 x 40mm) 285 constructed by war end. All up I'd say there were less than 1000 non-German SP AA constructed on tank chassis. In comparison there were around 4000 US M13 & M16 (2 or 4 x 12.7mm on half track) constructed, as well as British and Soviet truck mounted SPAA outnumbering their SPAA on tank chassis.
At best SP AA on tank chassis comes to around 15% of total SPAA production, and when factoring in the many additional thousands of vehicle towed AA guns that do not seem to be represented in the game at all, they would be lucky to come to 5% of total mobile AA production during the war.