This game doesn't support GVs. They have to hack the airplane code just to get things "on the ground". GVs are the most buggy, most unrealistic, most unimportant aspect of this game.
Yes, we have them. They're not going to take 'em out, but 99% of all tank activity is against other thanks that have just spawned. That's a fact. It's all spawn camping. There's no set battles, with 2 lines of tanks opposing each other, using battlefield tactics, or anything. Either folks use M16/Osty for base defense, they use M3s for supplies or troops, or they use tanks to take down towns (1% of the time) or spawn camp helpless victims (99% of the time).
This game just really isn't set up for GVs. The same way it's not set up for first-person shooter perspective. Instead of asking for more GVs maybe you should petition for better GV play quality. I'm doubtful you'll get it but it's worth asking for.