So what's the intended counter to the Jackson if I might ask? According to your previous posts it's not the stug, pIV, PV, JP4, or PVI. What is it? Or is the Jackson supposed to be top of the food chain for a lower price?
The Jackson is literally the top of USF AT, then there's nothing for a long time until Bazookas and AT-guns come into play. The JP4 is the counter to the Jackson, however both are tank destroyers and should inflict reasonable damage on each other or else there would be no point in building one or another. If you fear the Jackson becoming OP just compare it to the Firefly.
Also, how does one shot from a panther or Tiger out it out of combat? Last I checked 600hp-200hp= 400hp not 0. Does the Jackson get a main gun disabled at 400hp or something?
It also has 10/15 extra range than the tiger and panther while still being faster than both (except slightly slower max speed that panther) meaning it can kite.
The Axis have something called Blitzkrieg or Combat Blitz, both offer tremendous buffs to mobility, survivability and in case of Combat Blitz even accuracy (+100%). Once these units give chase to a 200hp Jackson not even a snare will save you.