At first, I thought the maps would merely represent the approximate topography of a given location...

But at least in the case of Vollmerz, it's fairly accurate. For example, the minimap roughly matches the view from this location and at that altitude of the area : https://www.google.com/maps/@50.3384148,9.5903402,5200m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

The rivers, or rather small streams, are immediately recognizable, such as the Kinzig and its tributaries, although they're mere streams a few meters wide and detectable from a bird's eye view as treelines as is typical of small streams.

The double-tracked railroad in the eastern part of Vollmerz can also be seen.

The biggest differences seem to be some ponds that don't exist, at least on today's satellite imagery. For example, in-game, there's a femur-shaped body of water west of Bravo in this video, and north of a river splitting Vollmerz in two : https://youtu.be/p-5k_iDQMn8?t=96

The river is the Ramholzer Wasser, which seems to flow underground between Hauptstrasse 1 and Hauptstrasse 29 : https://www.google.com/maps/@50.3398863,9.5962355,307m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

The 2 bridges across the river would be the Borngasse and the Hauptstrasse.

The ratio between distances in-game and IRL seems to be 3:1, i.e. 3km in the game is 1km IRL, and the small hamlet between Alfa and Golf would be the area around the Ringstrasse, with the Hauptstrasse on the western end of the femur : https://www.google.com/maps/@50.3420674,9.5947958,563m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

This would imply the femur would be around 300m long, and the road on its northern edge seems to be a composite of an unmarked road splitting some fields and the Sonnenweg loop west of the railway station : https://www.google.com/maps/@50.3407143,9.6004615,460m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

Echo is where two rivers meet, with a bridge crossing it and a small compound next to it. The river would be the Kinzig flowing from the south, the bridge crossing would be part of the Mühlenweg and the compound would be the 11 and 12A Mühlenweg : https://www.google.com/maps/@50.3403639,9.5882792,307m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

At this timestamp, the village in the distance under the score bar and to the left would be Sannerz : https://youtu.be/p-5k_iDQMn8?t=1243

Notably, in-game Sannerz features a twin-spire church, or even cathedral with this size, that doesn't exist IRL.

The river flowing from Sannerz is the Kinzig, and the main road to its left connecting the two towns would be the Hauptstrasse, with a forested hill squeezed between the railroad tracks and the Haupstrasse : https://www.google.com/maps/@50.3303882,9.5946306,2317m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

Another example of identifiable compounds is along the Mühlenweg/Engelsweg road ; at this timestamp, there's a compound between Alfa and Delta, one on Echo and another to its right (west) of it : https://youtu.be/p-5k_iDQMn8?t=1447

These would respectively be Mühlenweg 14, Engelsweg 19 and Engelsweg 17 as seen here : https://www.google.com/maps/@50.3417825,9.5770986,689m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

At this timestamp, my M109 platoons are in a deployment zone near a road with an S-bend, south of a river : https://youtu.be/p-5k_iDQMn8?t=1953

If going eastward on that road, there's another road crossing it at a 120-degree angle to its right. This description would fit those unmarked roads delimiting fields south of the Greenelbach stream : https://www.google.com/maps/@50.347374,9.6177072,709m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

At this timestamp, there's a bridge crossing on Foxtrot and my M113 Infantry platoon is dug in in some tree patch at a road junction : https://youtu.be/p-5k_iDQMn8?t=2056

The bridge would be the Hauptstrasse crossing the Grennelbach and the patch of tree would be the one at the center of the picture : https://www.google.com/maps/@50.3463203,9.5845914,795m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

Although we don't often get to see it in a Meeting Engagement, here's an in-game view of Sannerz : https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3331990959

Compare with IRL Sannerz : https://www.google.com/maps/@50.3204711,9.5898788,1193m/data=!3m1!1e3?hl=en&entry=ttu&g_ep=EgoyMDI0MDkxMS4wIKXMDSoASAFQAw%3D%3D

The in-game twin-spire cathedral would be located southeast of the Akazienweg-Ahornstrasse junction. The compound southwest of the town would actually be the Grill Hütte Sannerz.