Likely do to the way the games model system works, and likely the same reason they don't have weapon replacement system like it was on the BFR in PS1 for ps2 vehicles. Each model is a unique code that identifies the model, switching the tanks texture will likely require the vehicle to be removed from the world then a new one would have to spawn in at the same location.
No, that is not what I mean. I mean literally just changing the color after the vehicle is hacked. Not the texture. The color. So those spots with blue/yellow would have the same texture, but they would only be colored differently from the basic camo when it is hacked. That, or just change the whole camo to blue/red/purple when it is hacked.
Texture is the color, the Camo goes on to a static area and doesn't change, smaller tiles on the side like they did are likely set Dynamic, IE directly tied to the faction ID, like the base banners. Switching the Camo covered area to use faction colors would mean this area couldn't accept camo ID Codes. Example of an Hex ID might look like this: C742AB 0002 0005 0152975AF 02 Base ID \Turret ID\Secondary ID\Camo Code ID\ Faction ID The Numbers would all be mashed together. The first set Identify the Vehicle base where the turret is mounted on (Vanguard/Prowler/Magrider/Lighting), Turret ID says which turret is mounted and its values (AP, HEAT,HE), Secondary ID is like the Turret ID but for secondarys, Camo Code would tell what camo type it would be as there are many camos this code would have be quite long, finally faction ID would be short as there is only 3 factions (I used a two digit number they could have used 1 or even more digits). Also if someone has a nice camo texture that matches the continent your on why swap that out for flat empire colors when you would likely put the same camo on it.