OK, so I got the guilds waiting for me to take the portal and lead them into Cold Harbour.
Only problem, I still had to go and talk to Varen and the others. So, I did that, we're now 5 companions and all is good. So, now the only thing I can do is go back to Mournhold and take the portal back to the island and lead the guilds into Cold Harbour.
Seems there's an issue here because I'm going to have to fight Molag B with the companions (and use the amulet at some point) and the guilds. Or, am I not understanding this correctly.
Or go down with the guilds, attack Molag B, and then what. I guess what I'm looking for is, what is the sequence of events?
Thanks for any help.