Quick thought on this subject. You know how Lan is the last king of Malkier. His name was Lan Mandoragon before he was "crowned" and Lan al'Mandoragon after. Is this a possible hint into the identity of Tam al'Thor. Was Tam al'Thor a royal person at one point, which would hint to his son Rand al'Thor who would be the King of Kings. The only refute is it seems that all the Two Rivers has an al' but only in the two rivers have I seen that happen with their last names.