So, for the launch of third party ports on Switch in UK, we have those results (rounded)
Skyrim > 5,700
L.A Noire ~ 4,100
DOOM ~ 3,500
If we compare those sales to games like Splatoon 2 (28K), Mario and Rabbits (between 15K and 23K), and 12Switch (does anybody have any kind of estimate lol?), i would say that those results looks absolutely reasonable.
If years old port can do those numbers, a Switch version in line with the release date of PS4/XB1 version can definitively do some good numbers. Not great, but still legit results.
Do we not know fifa? It had the 1% at first and now 3%