I mean I guess it depends on what you define as transitioning smoothly ... as in graphics? Overall presentation? Mechanics? Innovation? Sales? Reception? If we are to consider Let's Go a smooth transition, then yes, all these developers should be fine. Though Intelligent Systems is hopefully making Fire Emblem Three Houses look a little cleaner by now.
My predictions in terms of sales.
Fire Emblem: 5-6M (5-5.5M best guess)
Pokemon: 18-22M (18.0-20M best guess)
Animal Crossing: 17-20M (18-18.5 best guess)
Luigi's Mansion: 7M
Link to the VGChartz Discord server: https://discord.gg/2uMTaYtv