This is my opinion of a scandinavian tech tree which should be in World of Warships for many reasons.
The Royal Danish Navy has been around almost since the start of naval combat, and has always been a nation you want avoid when it comes to naval combat. Except at the first world war and the second world war. Which is a bit onfortunate for the Tech Tree :/
The Royal Swedish Navy and The Royal Norwegian Navy have also been around for a long time. So for me it only seems fair that these superpowers in naval history, get a spot in World of Warships.
I don't really know how to rate them, so many might be wrong listed, but here's my version. Feel free to comment on their ratings and adding new ships, or just commenting about other things, and keep it positive
Ships that don't fit into the Tech trees, maybe premiums, could be:
Ilmarinen. A finnish Coastal defence ship, which probably would be listed as a Battleship.
HMS Sverige. A swedish Coastal defence ship, which probably also would be listed as a Battleship.
Both of them had a lot of firepower and were built to match the new warships of their opponents.
The famous Cruiser HMS Gotland. This swedish cruiser is probably more famous for it weird design and being more of a recon ship. It carried 6 recon planes (capacity for 8).
I HDMS Absalon (Denmark)
II HDMS Heimdal (Denmark)
III HSwMS Fylgia (Sweden)
IV HMS Oscar II (Sweden)
V HDMS Valkyria (Denmark)
VI HDMS Niels Iuel (Denmark)
VII HMS Tre Kronor (Sweden)
II HNoMS Sleipner (Norway)
III HNoMS Bath (Norway)
IV HMS Klas Horn (Sweden
V HDMS Huitfeldt (Denmark)
VI HNoMS Stord (Norway)
VII HMS Öland (Sweden)
X HMS Halland (Sweden)