Its disabled by default, no?
Anyways CVAR in question is g_realism

I meant specifically for those mods, because they are forced there and can't be changed.

I already found out that i have to change it in /steamapps/workshop

Nevertheless, thanks for replying.

Mods will copy the settings of the base game when first loaded, and then maintain their own separate settings from then onward. You can delete the mod folder (I think it's in your Documents subfolder), launch the game, disable realistic movement, and then launch the mod. The mod should now be using that setting even if you enable realistic movement in the base game later.

I think it may be true in most mods but I had realistic movement off and Enemy Territory and The Dark Army, had enabled realistic movement.

Further on in Enemy Territory Realistic Movement option is grayed out and in The Dark Army there is no Realistic Movement option in menu.

I just think in case of those two mods developers specifically didn't want players to play without it, and I don't enjoy playing like that

Yes if it's explicitly shown and grayed out, that means the mod enforces its own setting and cannot be trivially changed. "Author intent" and all that.

When I run into that, I either try to give it a chance, or decide the mod just isn't for me. Generally the hassle of trying to forcibly change it isn't worth it for me.