After populating a few longboats with seated Vikings, here is a set of Vikings standing at ease.
They are standing on their boat looking at the scenery, either while the boat is under sail or while their business associates are rowing away. At their original size they come out as ca 22-23mm for each figure, or 1:72 scale. This matches my own purpose for them, but it requires using the best available resolution on either your FDM or your DLP printer. They will print out with better quality and look more majestic if you scale them up a bit, say 128% for 1:56 scale.
I have included pictures of some prints at 1:72 scale on a resin printer (0.02mm layer height) and at 1:25 scale on a FDM printer (PLA, 0.06mm layers).
Also, notice that the left arm is often free and not doing much. Maybe they are holding onto the rigging or onto the side of the hull, but they just as well might be asking you for some shields....
Update 30-04-2020: added some new versions now with different positioning of feet, bumps in the cloaks and mail shirts (brynja) ironed out and the short spearman ("Ubbe") sized up by 5%. Also added the later kite-shaped shield as an option for Norman-type scenarios.