This is Because Most the feuds people request normally involve more than just 1 on 1, For Example - Undertaker vs Edge 2007 Feud - Batista is also involved in this alot (Armageddon 2007 its a triple threat match for the title ), Also Edge has his "Family" that help him win, so they would be in the story aswell,
most feuds the first two people are the Main Characters, the rest normally only have a small role!
if you know a feud that is just a simple one on one i will be happy to make it for you, or even a make Custom style feud (just make up a random story)
but you dont HAVE to make everyone that was actually involved have a role
you could just have a step that has edge as the loser but name the step "looses to batista" so that you know what happens