lol no...
It is definitely possible under the right conditions. I have had multiple vet two or three Pioneers without flamer upgrades in some team games.
I would like to see Pioneers and Combat engineers perform slightly better in combat if not at vet 0 then at vet two or three. CE's used to be ok in green cover vs. a Gren or Volks in the early game but got nerfed and Pios have MP40's which I think should be buffed a little bit for any unit using them.
Then again, I think this is just a symptom of veterancy for every faction besides OKW and UKF being pretty poopy to begin with.