I think he'd be a better defensive 1Bman than Casas after just a few short months of adjustments. His main issue on D is throwing, not glovework.
I do worry about his footwork, and at 1B, it is very important. Maybe playing Casas and Devers 81 games at 1B and 81 games at DH would allow them to get more ABs, due to less need for full days off, and perhaps even lessen their chances of injury.
If Mayer turns out to be a keeper, maybe we can shift Story to 3B. (Not sure his arm can handle it.)
C: Wong-Teel
1B/DH: Devers-Casas
2B: Grissom (AAA: EValdez/Yorke)
3B: Story (AAA: Meidroth)
SS: Mayer (Story/Grissom)
LF: Duran (Refsnyder/Abreu)
CF: Anthony-Rafaela
RF: Abreu-Anthony
With the pitching staff looking more encouraging than it has since 2018, maybe- just maybe, we can become relevant sooner than some seem to think.