Would anyone like the idea of Pokemon and their trainer working on a Harvest Moon/Story of Seasons like farm, that's nearby a rustic but charming town?
Grass pokemon planting seeds, water pokemon watering the crops, and you'd have Miltanks, Mereeps, and Wooloos.
I can imagine flower shops with a chikorita working as a mascot. And a meowth living in the general store.
Honestly, your scenario sounds more like a Rune Factory fan game than a Harvest Moon/Story of Seasons fan game, since I assume that you would have to go out, battle, and catch pokemon, in order to get them on your farm. I could see such a game working.
That's basically Re: Legend, too. The monsters you tame will help you with your farming depending on their nature. As mentioned, Rune Factory did that, as well. I had to go out and look for certain monsters that I would never otherwise have bothered taming, like the goblin-looking things, to get my crops watered for me everyday. Using monsters could be a bit of a pain, though, since it depleted their HP and you wouldn't get any runeys if the monsters were doing your farming for you. Though generally I was fast enough to run out ahead of them to get the runeys myself.