i can see Randy turning heel and challenging AJ
Better then AJ vs Nak at Mania... Would put him over much more as well which is what's important.
How I would do it... Have Orton vs AJ at the Rumble. Orton turns heel and cheats to win the title. AJ comes out later in the Rumble as a surprise and wins it to go to Mania and gets his revenge and Mania moment regaining the title.
That would mean so much more then a "barn burner" with Nakaboring who hasn't done anything worthy on the main roster. Roman can get his title shot with Brock at FastLane or whatever it's called. No need to ruin another Rumble.
There's really nobody else that is worthy of winning the Rumble. AJ and Owens do not have good chemistry for whatever reason.