Finland already thinks it’s bad enough to have Sweden’s child hanging around all the time. Now he has to put up with the little brat speaking Swedish too! D:
The reason why FennoSwede turned into this good looking happy brat is because his mother spoils him rotten. Which is also why Finland doesn’t just stab him: Mommy would not be happy.
As mentioned before, Scania http://humon.deviantart.com/gallery/#/d2r8ybw and FennoSwede http://humon.deviantart.com/gallery/#/d2qn9v9 have almost identical flags. The only thing that differs between them is the proportions of it, which I can’s show on the characters. But you will be able to tell them apart by FennoSwede’s sunglasses and rolled up sleeves. He’ll not stay this small forever after all.
And Åland is there to remind you that he speaks Swedish too, so this was inevitable.
I think the "Finland is actually one of the smartest" theory would make sense though.