Oh yeah, i forgot the spoiler complication in this forum, yeah i will try to remember this. Yes your clothing is completely believable in the mod at least in my personal historian opinion.You are correct they are regional traditional dresses, still in use in some festivals. We call them "muinaispuku" it's not the same thing as a national dress or the official county dress but more of a reconstruction of the clothing used in the local area in Viking Age.
1. The first from the upper left is from Eura and its a more coastal variant.
2. Used in Perniö, "Aino-Perniö" means that the clothing is from the northern part of Perniö, "Aino" is also one of the protagonists in the epic "Kalevala".
3 Tuukkala is an ancient village that doesn,'t exist anymore, but it was east of Mikkeli.
4. Ancient Karelian clothing, but this specific dress was also used in the Oulu region.
5. "Masku" dress was used with by the Sami, and Lappid people close to Rovaniemi and Tornio for example. You can see that its simpler in design. The Sami inhabited much of Southern Finland during Viking Age, it was in the 12th century war when they were driven back to Lappi, where they make their home nowdays.
6 "Kaarina" dress, this is an error from the maker since this clothing and color style was more common in the Enontekiö area and Inari's Finnish settler population used this style frequently.
7. "Mikkeli" dress was used in the most eastern parts of Finland, also used in the Lappi area, more exactly in the modern Russian boarder area.
8. "Kaukola" This is even more eastern dress, while commonly used in the Karelian Isthmus area it was used in Kittilä also with same colors and themes except that the "underdress was orange or black.
And yes some of these are from hard to find books, for example the sixth picture from the start the black-white sketch was painful to find since even i didn,'t know a good search word.
It says : Full dress outfit of a Finnish man from Pagan Era, meaning from 200 AD to 1100 AD roughly(Finland was the last European country to be converted to Christianity, there were 5 crusades made into Finland)
. Constructed by Doctor Sakari Päls based on the excavations in Northern Finland and other areas. Notice the man wears "Klappenrock" kind of caftan and his sword is very Nordic in style.