Bit of a stretch to say 2 catchers need to be in the lineup most days. Stephenson getting an occasional day off from behind the plate at 1B/DH and one of them at catcher then, sure! Not sure how you draw the conclusion that Casali makes it more unlikely Votto to get any ABs at DH, going to be 40 in September coming off surgery for a torn rotator cuff. If anything, quite the opposite and now room for CES to be called up at some point in 2023. These moves make sense if done to protect one of their best players Stephenson to preserve his bat with regular rest days, less wear and tear and to finally bring up deserving prospects who need to be called up in 2023 with Moose gone.
At no time during the 2020 season when the Reds had Casali, Stephenson & Barnhart did any 2 consistently see playing time at the same time in the lineup at other positions. Maile & Casali aren't exactly known for their bats and can't see them employed regularly at 1B/DH while Stephenson is catching. May as well kept Moustakas than to trot out that lineup most days with both Casali & Maile at C and DH as that lineup serves no purpose offensively. When Stephenson doesn't catch, he's logged 24 games at 1B, 6 at DH. When not starting at catcher, freeing him up at one those spots sliding Votto over however Bell decides is the best offensive lineup and gets playing time for 2 backups at catcher who know the reality of the situation they are in as reserves. If Cincinnati still plans to use Votto predominantly at 1B, I don't see how it has anything to do with the need to get Casali or Maile ABs at DH.
More of a chance Cincinnati starts 2023 off with the awful lineup they ended 2022 with before playing any 2 catchers at once most days when you consider the rest of the IF with Steer, India, Barrero, Senzel in the super utility role, Newman, Votto or to protect Stephenson from the daily grind as he was used last year. Even Myers logged 25 starts at 1B and will get breaks from the OF at 32. A rotation of players will likely get 1B/DH at-bats than any one player dominating the positions. I don't blame Cincinnati for playing it safe adding a couple of veteran catchers after the disastrous season behind the plate but we'll see if the season ends with all 3 or not.