That's the idea.
The jackson need to be powerful enough to counter the likes of king tiger and jagdtiger. There isn't really anything more powerful for the USF to use, aside from the super pershing.
The jackson need to be buffed and it was a question of how. Making it into the ultimate kite still mean the german can punish bad play.
I understand your idea of making the jackson the last hope in terms of AT for the USF. But the fact is that USF always has a lot of AT in their infantry, plus a well balanced AT gun, plus almost always floating on resources (specially in team games).
Jackson doesnt need to be that powerfull to snipe KT or JT, because you invalide all of the others axis tanks aswell, specially OST: Panther, Tiger, P4, Stugs.