Usually they have.

Would be fun to be able to call artillerys while messing with the tank. Or any other wehicle.

Might be too powerful.

Maybe radiocalls only for the tank driver, or passengers?

If you are the driver, theres a way i like to use when i wanna call in a arty but still need the tank to support

Squad command modifier button (held down) + squad command button on your tank will make it so that your passengers will leave the tank, but the gunners will stay in

side effect is that you as the driver can get out and the tank will still be firing

after you finish radioing the arty in, get back in and press Squad command modifier + spacebar and your passengers will jump back in

useful trick to have when you are a apc driver