Its not supposed to go against them, so there is no issue here.
You might have missed it, but no matter how much vipper will argue against it, its anti infantry unit and armor helps against handheld AT tremendously.
Allow me to explain some basic to you because you seem oblivious.
All hand held AT weapons have deflection damage so the armor buff does "helps tremendously". Let me break this down in number so that you understand:
Pre patch/post patch chance to penetrate at range 35:
Ptrs 29%/27%
Bazooka 46%/42%
Piat 46%/42%
Those changes are anything but "tremendous." The impact for these weapons is very small since most of the damage they deal comes from deflection hits and not penetration hits.
Finally stop twisting my posts (in case you simply are incapable of understating stop making comment about them).
I never said that Brumbar is not an anti-infantry unit, I simply correct you description of it as "a pure AI vehicle", a description which fits the hezter better.
I also point out to you that there in rule that says "pure AI vehicle" need to have slow moving projectiles contrary to your claim.