Do you really want Sting's run to start and Shield's run (as a unit) come to end with Cena? Look at what happens to guys who work with Cena (friend and foe). I'd keep Sting as far away from Cena as I could. Sting's in his 50s, he can only do so much at this point that he needs to almost be like Taker, an attraction not the main focal point. Sting's whole run needs to be very carefully choreographed to maximize Sting's value to WWE (and to the Sting character). Shield needs to win Sunday or blown to smithereens (all 3 go their own ways) and get away from Evolution, they've done nothing really to reestablish Evolution other than Batista laying on his back more than 3MB since Mania. They put the cart before the horse, Evolution should have won the first one and this was the rematch.
This sounds like something out of the Vince Russo playbook of wrestling booking. Way too many moving parts and IMO it would cheapen the big belts. If you wanted to do something with the US/IC vs Tag Belts fine, but the days of someones like HHH and Austin being Tag Champs while being WWF and IC champ are long gone. It's kind of like how they had Rhodes Brothers vs Shield on the PPV for their jobs then the next night they won the belts. It was a great moments for all of them, if you had the added stipulation that the belts were on the line it would have made the match far too messy. Could you say Rhodes v Shield could have gone to the next PPV and THEN won the belts go ahead thats a whole nother story.
TNA already does something like this as I think it's called feast or fired. I don't think you'd want the same guy grabbing multiple "breifcases". The WWE has had a horrible time booking everything as it is let alone figuring out how to get the IC belt on tv because Orton's already defending the WWE World Title later that night (just one random idea).