On USF changes I'd say Jackson should be 600 hp or 540. 640 hp is too much for a turreted TD when used by a competent player even with the increased cost and nerfed moving accuracy.
The primary faction the new Jackson overperforms against in DBP is OST. Changing Jackson HP to anything other than a full revert will probably make things even worse than they were before.
In the best case, this won't change anything vs OST (stug and Panther will both require 4 shots each to kill the Jackson).
In the worst case, Jackson will continue getting 1-shot by sturmtigers, or 2-shot by HEAT shells, or 2-shot by JT/Elefant. This will make Jackson even worse in those late-game situations than before, since it now costs more than before.
HP has to stay either at 480 or 640, and something else has to give. e.g., we could drive damage down to 160, but increase penetration by 25% to compensate; that way Stug counterplay remains a possibility, and Jackson can perform its late-game role properly.
Also, RE receiving smoke grenades seems out of place and is a major nerf to USF infantry play. RE already function well as a engineer unit that can get weapons upgrades and putting smoke grenade on them makes little sense. It's unnecessary change that forces the US player buy more then one RE simply to have mobile smoke as the mortar takes ages to drop smoke at times. USF is meant to have smoke on their mainline infantry to allow major pushes with multiple points of smokes to covering different approaches. Aside from that the USF changes seem fine.
The reasons for moving smoke from RE to Riflemen are multiple:
- Giving smoke to RE gives them a combat role, where they lacked any before
- Removing smoke from Riflemen, makes them less of an 1-unit army that puts elite infantry into shame, but still allows them to perform well for cost
- This increases the added value of USF Elite Infantry, which were massively overshadowed by Riflemen; rather than being the non-meta option you go for to surprise people, those doctrines now actually become more competitive to non-elite infantry doctrines
- It allows RE to better synergise with USF Elite Infantry
- It prevents lategame USF play from degrading into Jacksons & Riflemen
- It turns USF army synergy from Riflemen-centric to Infantry-centric
- It allows USF late-game to transition to lower-upkeep Rear Echelons, without abandoning their smoke
- Incentivising players to build tanks other than Jacksons (since both M4 and M8 have access to smoke)
Finally, Riflemen smoke is massively powerful vs OST, where USF does OK against, and almost useless vs OKW where USF gets their ass handed back to them in spades.
To compensate for early lack of Smoke, the USF mortar is now the best smoke dispenser platform in the game. Try it out, and let us know how the faction feels.
If the changes work, without getting USF MG-pinned in the early game, it will be a healthier state of balance with more synergy involved.