I think Tuskarr should be neutral. Their are three tribes on the Dragon Isles, the Iskaraa, the Waking Shore tribe, and the tribe who lost their home of Imbu to the Primalists. Brena and the Iskaraa should remain neutral, while the other two can join the factions.
Meanwhile I think the Dracthyr are a cool addition to the game but I do wish Ogres were playable beforehand.
They really had an opportunity to have a new Horde (Ogres), Alliance(Furbolg), and Neutral (Dracthyr) race for the beginning of DF.
Side note: Of Stone and Fur could work as an achievement or story chapter title involving the Stonemaul and the Stillpine.