Is there any way to make my decal the exact size i want?

Look down and right and you will see black bar with first word “Alt…” that’s one you can adjust and rotate your decal.

I tried to do this at the video, but decal is either too small or too large

Oh, you did right. Gee…I am sorry. I did testing exactly decal, you want it and it didn’t line up perfect on Leopard 2-123. I tried schwarzhreuz decal and it almost perfect. Nothing I can help you but it may won’t noticed different in middle of battle. I hope you have fun time playing WT.

Fun fact is that before one of the updates you actually could perfectly line up that decal