Matrix Games Forums

The terrain type in a hex also determines the average
distance (range) for combat between ground elements.
This is important as it reduces the natural advantage
that some longer range weapons (such as tank guns) and
improves the importance of shorter ranged weapons (such
as infantry carried anti-tank weapons). Thus tanks will tend
to take heavier losses when attacking infantry in closed
rather than open terrain.

The last sentence is not rly that impactful or worth to think about at all from what I can tell (so far). Just the AFV breakdowns are massively increased in Swamps (at least). Combinations of Terrain+Fort may cause different effects e.g. Mountain+Fort 2 also caused way more AFV breakdowns then with Fort 0 somehow...so this overview in Fort 0 just gives an idea and I expect some caveats to the "multiplicative nature" of terrain+Fort bonuses in some cases but not all.

Here you can access the spreadsheet, you need to download/copy it so you can make your own test series by simply exchanging the 10 tests in the rectangles (if you use less than 10 runs make sure to empy/erase the "0" calculation in the sum line for the totals, so the yellow marked cells you need to fulyl empty/erase or the toal sum average is off [here the 108,6 cell]).
It is all set up to use the Clear Terrain results as the base for the comparisons between terrains. Use the numbers highlighted here:

I think a test should be made at the contrary IF you have the time, with a low tier division attacking.

I do feel that the Panzers in general - if taking excess of losses - may as well be glorified motorized divisions. By moving around already their amount of damaged tanks is nigh insane and to receive tank replacements is not really viable in '41.
Higher losses would turn Panzer divisions devoid of panzers in a few combats already.

Not sure what you are looking for/expecting.

If I make all Tanks be DAM before attack I would expect less Soviets hit, and the difference between terrains to decrease (since the terrain stuff is supposed to reduce the range benefit of tanks).

Attached a quick result. Funnily enuff less Germans DAMaged in Swamps since no Tanks are "breaking down in combat".