Re-jigged mine a bit. The show is a lot more Raw heavy but I think that is WWE's mindset and I think it's made up for if you give Smackdown the main event of the show. I think an eleven match main card is the absolute max WWE will go so there's going to be more multi-man matches than we like and also notable omissions from the card (like the Cruiserweights).
Matches in order of airing.
Pre-show:
Interpromotional Tag Team Match
The Club vs. American Alpha
André the Giant Memorial Battle Royal
Celebrity Match
The Big Show vs. Shaquille O'Neal
Main card:
WWE United States Championship Ladder Match
Chris Jericho (c) vs. TJ Perkins vs. Neville vs. Sheamus vs. Rusev vs. Big E
[Usual opening ladder match to get the crowd going, get all the important RAW mid-carders on the show. Big E or Rusev wins.]
WWE Raw Tag Team Championship Match
The New Day [Kingston/Woods] (c) vs. Enzo & Big Cass
[New Day reverts back to being heels around Rumble time, basically a clash between two most over tag teams on RAW. Enzo/Cass wins.]
WWE Intercontinental Championship Match
The Miz (c) vs. Baron Corbin vs. Dolph Ziggler vs. Bray Wyatt
[Same logic as the US title match with the SD mid-carders. Miz holds the belt all the way to Mania. Give Wyatt a WM win.]
Interpromotional Women's Tag Team Match
Charlotte, Dana Brooke, & Nia Jax vs. Becky Lynch, Nikki Bella, & Alexa Bliss
[Some titles will need to be sacrificed to get everyone on the card. I think the SD Women's title will be the case. WWE values Charlotte too much to put her on pre-show. Becky is the SD champion. Brand supremacy, etc. Smackdown wins, Bliss attacks own team after 'cause she's sick.]
No Holds Barred Match
Kevin Owens vs. Sami Zayn
[Owens get eliminated at RR by Zayn again, Owens beats the crap out of Zayn immediately after. Feud re-sparked. Owens wins.]
Singles Match
Dean Ambrose vs. Samoa Joe
[This will likely be thrown together last minute. Joe debuts at Rumble - Mr. Kingpin of Smackdown wants him to earn his spot. Either winning makes sense to me.]
WWE Raw Women's Championship Match
Sasha Banks (c) vs. Bayley
[Hopefully Sasha is a heel by now. Either could win tbh.]
Singles Match
Seth Rollins vs. Triple H
[Self-explanatory. Rollins wins obviously.]
Retirement Match
The Undertaker vs. John Cena
[Cena wins. Bye bye Taker.]
WWE Universal Championship Match
Brock Lesnar (c) vs. Roman Reigns vs. Finn Balor
[Lesnar takes the belt from Owens at Royal Rumble. Balor returns to claim the belt he never lost and gets put in a match with Reigns to determine the #1 contender. It obviously goes to a no contest. Meh story but that's WWE for ya. Balor wins.]
WWE Championship Match
Randy Orton (c) vs. AJ Styles
[Orton takes the belt from Styles at Survivor Series and holds it until Mania. Styles loses his rematch at TLC in questionable ways. Cries for another rematch because of questionable loss but doesn't get it so vows to win the Rumble. Does that. Styles wins at Mania. That's right, ending on a heel win.]
The more I type out that main event scenario, the more it seems like a face road to Mania and not a heel. Whatever, someone think of a better way. Point is, I want Styles and Orton (or Cena if Taker can't go) at Mania.