Tanks now have owners and it is possible to attack the opponent’s tanks. The loss calculation algorithm is very simple, but good enough for now.
I have also drawn another tank, which is supposed to look like the Swedish m/40.

In the screenshot, a group of German tanks are trying to make their way east to the Swedish naval base at Karlskrona, but their path is blocked by a lone Swedish tank using the lakes for protection.
I gave the Swedish tank a slightly different color to make it easier to tell friend from foe.