Boy you guys have been hard at work on this. I racked my head on it for a few days that's for sure, and I'm coming up with the same thing. That Crinan came from three brothers... and the reason he was selected as a King in Stead of Malcolm II was because he descended from Niall of the Nine Hostages, from what I can see.
if Niall of the Nine Hostages really is Crinan's direct great or GG grandfather, then at least we have something to fill in the gaps with between him and Niall. That's where I was running into a brick wall was at Crinan's grandfather.
It would be amazing to see this envelope pushed back farther than 980A.D. It's amazing it's been tracked this far, but... you guys all have my attention on this one, and I'd be glad to assist any way I can.. as this is my goal... to track down the break in the line... so far, there hasn't been one and I am truly stunned by that.
We gotta find it guys.... or our curiosity will eat us alive. : ) lol ~