The slaver coalition taking orders from the Yunkai seems ludicrous to me. Astapor was the city that had the expertise to “manufacture” slave soldiers and in comparison the Yunkish “troops” are literally the most ineffectual cannon fodder imaginable. New Ghis has the infrastructure and the military know how to equip tens of thousands of (and one assumes the leadership), on paper, effective soldiers. So why is the more military competent power following the lead of yunkish commanders?