Well, The UFC don't have a lot of new fighter every events to fight in the prelims like the others organization.
I mean, almost everybody in card are well known and it is normal to have some big name fighting in the prelims.
If Koscheck and Fitch are in the prelims, it is perfectly normal to have AA there too.
i see the main card like that :
Silva / Hendo
Kongo / Herring
Sanchez / Bielkheden
Okami / Tanner
Leben / Sakara
So , basically, a lot of big name will eventually be in the prelim no matter how they set-up the card.
Fitch , Koscheck , AA , have to win by quick KO or Sub and they will probably have the time to show their fight on the PPV part.
I would prefer to see Fitch in the main card than Sanchez and some would prefer to have AA instead of Leben or Okami, hard to make eveybody happy.