Half of the guys you listed in the "potential upside" section of your post will not see a single major league AB in 2026. I guess I could have specified I meant 2026 upside, but the topic was the state of - and upside of - the lineup in 2026.
Under "big improvements", don't agree with any of those listed. Not sure why we'd expect big improvements from 28 and 29 year olds when their 2025 numbers were on par with or near the top of their career numbers. Vierling didn't play, so hard not to improve on that, but in terms of lineup impact, will he be an improvement over someone like McStinky or Baez (who would likely lose ABs to Vierling)? Maybe. Big improvement? Not likely.
Under "still have another gear", I see 2 guys in Greene and Tork who should be in the "they are who they are" section. Re: Keith, I truly hope he has another gear and he's about the only guy I'm holding my breath on in terms of marked improvement.