Race was never a core aspect of the Finnish identity. It was mostly about the language and the culture. At least it wasn't about the race in a way it's to Germlings and such where you come up with some autistic biological traits to classify people by.
Finns always identified Slavs and Swedes via the differences in language and culture, rather than by physical appearance.
So if your goal is to be some uber HC conservative Suomi pro, then having race be on the top of your hierarchy of values is not the way to go.
This doesn't mean that now every Somali that speaks Finnish is 100% a Finn, but what you are doing is not exactly in-line with Finnish culture either.
I'd say, if someone isn't clearly some kind of sand-man of the deserts, gypsy etc then it's all good as far as the racial stuff is concerned.