Done it except for one boss. Gruthaz.
So far as I can tell from published maps this guiy is on an island off the cost of that olace with the little house (steps leading up into it). Trouble is - that Island does not exist in my version of the game. Even the 'little house' island is only big enough to carry the house - none of the rest of it exists.
So - now what do I do??
He is on island number 3 in attached link.
tamrieljournal.com/public-dungeon-group-challenge-conqueror-guide/
^ cp 549 characters - best game ever playerd ( actually the ONLY game ever played so who am I to judge others).:D