The root of the problem is that Relic buffed it multiple times and then made it available earlier and set it in the tech tree so that everyone would build it.
That bears a close resemblance to HMG42 description

Though solution could also be lowering damage and increasing accuracy, which would keep AI dps at intended level while diminishing effectiveness against light vehicles.
Kubel though should be torn apart, its T0 car, not even armored one, its just a car with MG.