I played a while with odin, you only have to build a great econ (do it like you play with greeks, just build villagers all the time and build a trade-route very soon)
, put 2-4 hillforts up and spam jarls, huskarls and rams like an idiot - nerve him with walking woods, so the greek or egypt enemy simply has no chance against this, if he builds hypaspists and prodromos he will run out of food very soon, but you only need little food, a decent amount of wood and a lot of gold (not a problem with dwarves and trade-route). If you get low on gold, just spam a few hill giants.
I got to 1850 rating, where I stopped with these lame tactics (I lost only 2 times, so I did not stop because I could not get higher - just got bored)
The norse units are maybe not overpowered, but the whole civ. They get too cheap upgrades and buildings, compared to the best economy in the game.
And I think norse units have too much hack armor, especially the myth units.