Forgive me for another Invasion question

Why in the blue world would Shane and Stephanie be the heads of the Alliance, respectively, or in any way?? You could have had WCW or/and ECW as threats with heads Heyman or/and Bischoff or whoever else. Keep it at least halfway believable and real, build on real animosities/heat/rivalry built up for many years during the federation wars plus some dream matches. Who would believe that Vince's kids would spearhead two organizations they had no connection to, just to kayfabe one-up pops?