The M36, SU-85 and Firefly are all good at kiting. It's how they're designed to operate.
The Jackson would not be the problem unit it is if diving it killed it like it kills the SU-85 and Firefly.
I don't know how you can call Jackson "the hardest to dive" out of all allied factions.
USF is already the easiest faction to dive because USF has:
No nondoc mines that give engine damage(I don't count those garbage 10 muni mines that slow that noone uses)
Limited AT nade(no vet1+ rifles no at nade)
Bad handheld AT(zook)
Bad AT gun against prem mediums and up.
While soviets and brits have:
Nondoctrinal mines that give engine damage
More available AT nade(debatable for brits as there's not many RE squads, but if they are they are probably near the tank.)
Very good AT guns.
Soviets might have PTRS penals with satchels.
Soviets might have Guards with button vehicle that is extremely potent against unsupported tanks.
Soviets might have one of many other AT commander abilities.
Firefly can stun and blind tanks from a long range
SU-85 CAN SELF SPOT(people seriously underestimate this ability, which also means it will see the dive coming)
If your argument is that jackson can just drive away, guess what so can both firefly and SU-85, and those factions have way easier access to long range vision.