Vanira (Vol'jin's second in commmand)
Rokhan (The Horde's "best scout" according to wc3)
Gadrin (Leader of Sen'jin Village and Vol'jin's mentor)
Volrath (Leader of Spear of Vol'jin)
I reaaaally don't see Rokhan as a leader.
Sure players "know" him and he's also a Shadow hunter but I find him to be a... token character. If he had been around during the Darkspear Rebellion at least we could have get to see him developing leadership skills and even in WoD he just stood there in the Garrison to inform us of some things.
I just don't see him leading the tribe.