Historically swords were rather rare among warriors. Rich warriors, ship captains, Jarls were able to afford one. The standard viking weapons were axes and spears.
I dont say that they didnt exist, but there were something like one or two swords by clan. In the late viking era they were more common.
The predominance of the axe comes mainly from that fact that before being a weapon, it's also mainly a tool.
Now that being said, as said by many others before me in this thread, it would be silly not to have swords in the game, especially as we have flails and hammers, two weapons vikings almost never used during the whole viking period...
(yes I know, Þór's hammer blabla, but no, except the god, no battle hammers for vikings. I'm pretty sure that not a single warhammer were found by archeology in northern europe. They are almost as legendary as the horns on the helmets :p )
And a game about vikings without Ulfberht swords, cant be a good viking game! :nonchalance:
https://en.wikipedia.org/wiki/Ulfberht_swords
http://draksen.net/images/Thorfinnr_signature.jpg