Sierra I know your a career troll, but I'm going to humor you anyways.
There is a mechanic within coh that is fundamental to all ballistics. It involves scatter values to rng the path the projectile will take and the size of the target.
AT gun vs kubel: The at gun misses frequently. You say light vehicles have paper armor well the kubel is about as light as it gets, but it's impossible to hit and it gets harder the closer it is to maximum range.
JT vs light vehicles: JT wtfpwns light vehicles in violation of the principle above. I kind of see it as trying to hit a tiny nail with a big heavy hammer instead of using a smaller light hammer. This is supposed to be why it sucks vs infantry too, infantry target size is very small and jT should have no or very little splash. The value is too low currently, because it should be missing light vehicles much more than it does. It should rarely miss mediums. It should never miss a heavy.
The next thing you say, Germans have nothing that comes close to wiping infantry squad instantly? This is how I know 100% your trolling. Many German tools do this. Mortars, rifle grenades, bundled grenades, PanzerIV(w/pintle), sturmpanzerIV, panzerwerfer, Tiger, flakht(beta version), stuka, King Tiger, and the best in the game STURMTIGER!
1: I'm not a career troll you ass, I'm actually extremely fuckin serious and frustrated enough with the shitty way the game has been going that I've uninstalled completely as of 10/25/2014.
2: I'm not disagreeing that the Kubel needed to be made bigger, easier to hit with ATG's and Bazookas, people missed to often. The +5 Fuel cost was overkill/nerf onto the only non-doctrinal suppression method the OKW has! Especially since they are already a terribly resource starved faction.
3: Bundled grenades are dodged like any other grenade, rifle grenades same thing, Mortars are relatively easy to dodge and don't have the "precision drop" ability or the explosive power of 120mm mortars.
Panzer IV's do "okay" against infantry, but not excel. Brumbaars? Who even makes those? It's locked away in stupidly expensive Ostheer T4-Land.
Panzerwerfer can't hit much when it's rockets are spread so sparsely at maximum range saturation fire doesn't help either. (Too much scatter, overnerfed)
FlaK halfrack is just crap, it hits the ground more often than it hits infantry. Though getting rid of the goddamn deconstruction timer just to move was a smart change.
Stuka is good, but expensive and comes in late, horribly delays teching.
King Tiger's are okay, but don't insta-gib squads in a single shot. Also they are terribly, terribly, terribly, terribly slow. Their range is that of punching distance (On guns that were lauded for their extreme range and penetration values at those ranges!)
Tigers are okay but definitely lackluster from their original selves.
Sturmtigers, hah, good luck with that. One shot to hit and you have to give away the fact that it's there just to be in range and drop the shot. By that time all enemy infantry blobs will have insta-retreated back to base. Not to mention that the damn projectile detonates on a slightly strong gust of wind or a butterfly before landing where you want it to. (I know Relic patched it slightly, but not nearly as well as they made it out to be.)