-If there are no buildings > you are doomed
-If opponent uses truck push and makes no mistakes with Kubel > 
-You go for LT > he goes for AA HT + Puma
At the moment i don't see how you can come ahead on this engagement:
2Rifles or Rifle+AE
RE
vs
Pushing/Breaking building truck
SP
Volk
Kubel
That is true, unfortunately.(Will have to pray to the RNG God his Puma micro is awful)

Though having an MG + Lt. out does help I find.
There is one way to counter a single Kubel push though, I've recently discovered. Unfortunately it requires getting a Rare commander(Easy8 doc). Basically you deploy a vetted rifle squad early on, and hope you're able to at nade the kubel by surprise. Then finish it off.