I got a few sprues of the Wargames Factory Vikings a few days ago. I put one of them together to see how it would look. I had originally intended to give him a sword and shield, but they looked goofy when I test-fitted them and I gave him a bow instead. The picture features the Wargames Factory archer on the left, a Foundry Viking in the middle, and a Gripping Beast Saxon on the right. I was going to have all three be Vikings, but I grabbed the wrong Gripping Beast box and was too lazy to go back upstairs.
To my eyes the Gripping Beast figure fits fairly well with the Wargames Factory sculpt, while the Foundry figures look a bit shorter and heftier than the others. The difference isn't enough that I would feel uncomfortable mixing all three on the table together. I'll probably mix and match what I've got and fill out the rest of my purchases with Wargames Factory.