If you have these three names, that's for sure you are looking for places to see Northern lights. Check this link for complete details on Northern lights and info about these 3 places:
https://blog.tortugabackpacks.com/northern-lights-europe/
I have been to Sweden its a beautiful place but but Norway is the most travelled and liked place by everyone.Last year when i was planning the same i landed up to Finland and Norway both but somehow i couldn't travel because now is the time to see the Northern lights.And in Finland there were those
I think it should be finland, norway and sweden based on my idea. There are so many places to visit in finland and Oulu (https://travellifo.com/14-best-attractions-of-oulu-finland/) is one of such places. If you visit Finland one day do not forget to visit Oulu.
I would suggest Norway . Visit Norway for a week and you can cover Tromso , Oslo and Bergen . If you are visiting anytime from now to March end , you stand very good chance of spotting Northern Lights