The Usos vs SAnitY (Smackdown Tag Team Championships)
When Sanity first debuted on the main roster, they went straight after one of the most accomplished tag teams on Smackdown: The Usos. But after a 6-man bout which also featured Jeff Hardy, this rivalry died quickly for no apparent reason.
While the Usos have been fairly consistent in their appearances, Sanity have missed many weekly shows and PPV.
I arrived at this match by the method of elimination. Firstly, one team out of The New Day and the Usos will be involved at Mania to bring the necessary star power. Since the New Day can handle a management role, it is likely that the Usos will get a shot.
Secondly, one team out of The Bar and Sanity will participate in the match. As we have already seen The Bar vs The New Day and The Bar vs the Usos on various occasions, Sanity should get the opportunity.
Whilst the possibility of this match is a lot less as Vince doesn't seem to trust Sanity, it is the logical option. As all the other pairs have already had matches, even on weekly shows, it seems improbable that the same will be repeated at Wrestlemania. Hence, the Usos vs Sanity is the best option in WWE.