If that Street Fighter port can sell half a million at the price it was then FIFA will sell over a million over time easily maybe more.
Non enthusiasts / casuals couldn't give a fuck what engine it runs on lol.
FIFA on Switch is going to be a massive successes. You are dead on, only gaming enthusiast care that it isn't running the latest and greatest engine. The pick up and play nature of FIFA games and the ability to have multiplayer wherever you go is gonna be what sells it. I'll be getting it for sure and haven't bought a FIFA since PS3.