Paul Beakley
> […] than if we’d just invented the connections ourselves […]

I imagine your group understands the ins-and-outs of Icelandic society circa 900AD, and these connections are easy to make up. Have you tried it with a group completely new to the setting? The relationships alone don’t feel like they’d get it “right” if you’re unfamiliar.

The premade trees show unfamiliar people How It Should Be, I think. Once you have some sessions under your belt, or have watched enough Vikings on TV, you could probably just wing it.