>>37354988But using the starters would miss part of the appeal of Tamagotchi, and Digimon by extension. They have branching evolutions; you're not guaranteed a specific Tamagotchi or Digimon unless you're willing to work for it. Agumon is well-known to become Greymon/MetalGreymon/etc., but this is only a reward for caring and training it well; it's just as capable of becoming something like Numemon.
Eevee is the only one that can work in this format because it has branching evolutions, while everyone else gets just one, sometimes two. If you want a Charmander Tamagotchi, then you'll have to account for it becoming something other than Charmeleon and Charizard, because having a Tamagotchi care system in place would be pointless if it becomes the same thing no matter how you care for it.