Pretty self explinatory. I have noticed the pak43 regularly shoots through buildings, if sight is given. Is that on purpose? Often enough, placing pak43 behind a taller building will render it immune to all but vertical offmap, since the house in front can soak up all the arty from your base or the front lines. Not to say that they have the same range as Scott. Makes it really hard to dislodge without a support from calliope doctrine for USF (or rushing major in and hoping the shells land on it).
Also, on maps like Hill400 pak43 bullets will regularly phase through the ground (as opposed to connecting like from all other tanks). Is that intended or is pak43 (and maybe 17pounder, haven't tested it) bugged?
They're intentionally designed to pierce all obstacles and slam into their targets or near the target. This is probably due to the lack of
BRACE and how easy PaK 43s are to kill (Very easy). Yes, intelligent placement can make it harder to kill the gun but its not like it can MOVE and shoot your face off outside its fire range.
Hill 400 is the Allied Arty players' dream map where the Axis base can be bombarded into rubble by SPG spam. No PaK 43 will last long there.
17 pounder cannot normally shoot through obstacles but they do have a piercing shot ability that temporarily can, like the Jagdtiger. 17 pounder can brace but is also a meme emplacement.
Easy counters: Any arty call-in. Skill Howie. IL-2zzzzzzzzzz. CalliOP. Any squad up close with a gun. Tanks up close and circle-kiting. And so on.