Yes, I totally agree. I don't think the problem is just performance. There are design decisions for balancing I would guest. But I really don't like it neither. Maybe you can keep the 3d person camera for helping to have a view around you. But if you want to shot, you must be in 1st person and use the tank phisical controllers (wheel for driving and joystik for cannon?) with a monitor that shows where the cannon is aiming to. It would be much more immersive.

Other option and more realistic would be to be able to open a gate and go out with just the head so you can have a better view in front of you and in your sides. But making you damagable by a headshot. Something like this image:

https://c8.alamy.com/comp/2HNCG60/non-exclusive-kharkiv-ukraine-february-15-2022-a-tank-driver-looks-out-of-the-hatch-at-the-kharkiv-armored-plant-kharkiv-northeastern-ukraine-2HNCG60.jpg