Often see those tanks in 4 but they are would objects without interaction.
In 5 it would be good if the tanks become interactable. For example you can take out the gunners guarding it, hop in the tank and cause chaos.
Concept wise tanks would be more tanky/powerful PA, to offset it's advantage tank would be a bigger/slower moving target making it vulnerable to RPGs/fatmen.
Also due to it's size the player can't use it on some terrain or indoors.
The tank runs on fuel and has powerful main guns so the fuel/shells it uses would be expensive and not available from every vendors, or the player can craft these with the right requirements but it would still take a lot of resource to make.
BOS/gunners would use tanks so the missile launchers/fatmen would become more useful, without them tanks can still be disabled with well placed grenades/mines, or gauss shots to the weak points. When that happens NPC would get out of the tank after a short while same as how they will leave PA with no core.
The player can then repair and capture the tank to cause chaos. A destroyed tank can't be repaired/captured however. It's a burning wreckage that will despawn after a few in game days.
Tanks can be upgraded in the same way as PA. Such as a bigger gun for better performance against hostile tanks, better MG for vertibirds/ghouls, and better armor plate for more protection.
