Profile of Esxile

Problem is not heavy tank but medium tanks. They are crappy vs other tanks and building two of them which cost more than a heavy tank (except for the T34) don't bring anything vs said heavy tanks.
On the same page heavy tanks deal better vs tank destroyer and having more health and more armor make them more forgivable in any circumstances.

I mean, do you build another light vehicle once medium tanks are out? nop, so why would you build a second medium tank when you know a heavy is coming.

Sanders stated it perfectly in one of his responses here, Medium are for midgame while heavies are for late game. And this is this logic that is broken. Heavies should be as much for late game than mediums. Having 2 or 3 mediums on the field should be rewarded more than having 1 heavy but that's the opposite today: bigger investment, bigger repair time, more micro taxes, more subject to lose all or part of your investment etc...

Soviet weeps in their fully teched corner..

But also perhaps a tech locked Jackson wouldn't be so bad. It could be coupled with a price and pop reduction at the same time and if it's delayed there wouldn't be as much need to neuter its medium performance (should still be lowered tho).
What's more, if it is moved to later, medium counters can be improved as well to help bridge the gap... It wouldn't necessarily be a bad thing on the whole.

I didn't mention Soviet because their tech system make it comes sooner in some cases for not so powerful units (T34-76), its difficult to define it and compare it to other tiering system. You can't really rely exclusively on Soviet T3 to win a game (outside of doctrinal options)

Jackson behind paywall is more like KT or Panther/brumbar or Churchill/Comet, but all of them comes as additional values with various advantages.
Jackson + Calliope behind paywall is more in line with how factions work or Jackson + Bulldozer behind paywall. There is a value to get behind the paywall other than I must because there is a panther on the field.

Could make HVAP much cheaper with vet like other shocks smoke. Not like vetted armour is an issue for usf, being able to swap crews around.

Also just because you might not always be rolling through the enemy lines doesn't mean having the ability to do so isn't huge. As a matter of fact that's part of why the Jackson is so strong--it CAN sit behind the lines like other allied TDs and work perfectly fine, or it can dive for that kill exactly like the m10 would but without making all other usf armour redundant.

Taking the step will help us see what else usf truly needs for stock at because right now we can't be sure as the Jackson covers everything absolutely and entirely.
Would buffing sherman pen help? Who knows. We won't unless we create an environment for us to properly test and as long as the Jacky Boi is omnipotent we never will

I think we are all well aware of that. We reached the point where everyone agree on Jackson being the best TD in game, there is no doubt about it. Does it mean it can be nerf solely on this assessment, nop. Because USF faction is still what it is and the faction would collapse on itself if not for the Jackson.

If the idea about the M10 is to add it stock and dedicate the M36 to counter heavies, why not. If it is about swapping M10 and M36 the idea is just stupid.

USF initial faction has been design around lacks and gaps and imaginative (or not) ideas to fullfil those with different and unique abilities. At the end the result has been to make certain units OP to cover the needs in regard to the impossibility to balance it. We're still in this situation with the Jackson which need to be able to stand alone on the late game. There is no Comet or Churchill to soak damage as for the UKF or Katyusha to wipe the floor from team weapons like for the Soviet.
I mean I'll be more than happy to make the Jackson a Firefly's clone (even without tupiles) if a +900hp unit is added to USF roaster or to make it a SU85's clone if Calliope come to stock.

The Jackson's design neither presents any positional counterplay nor allows the opponent to just buy a bigger gun (commanders notwithstanding). You can only counterplay it with non-vehicular AT. Otherwise it can only be outmacroed.

Then don't buy bigger but smarter, Stug in pair, pak40 or jpz4 perfectly counter Jackson.

Funny you mention it, but jackson has a healthy mixture of speed, penetration (plus extra pen with muni), health pool and attack range. On top of USF tanks perks (self repair, on the move acc)

It is like P4 on axis, a good combination of stats that make a unit solid. But P4 are not on the top of the food chain.

USF has many doctrinal units that could fill that missing space you mention.

Yes indeed, Jackson has a mixture of what the USF faction lack in a whole, thus my idea to give some to the sherman by swapping with Ez8 and reduce the Jackson TD profile to heavy tank counter.

But no, doctrinal units or abilities aren't there to fill a missing space but to add volume in each faction design.