dropping to Asuka is the way to go imo
if anyone but Becky wins the Rumble, Vince should step down immediately
If the plan is Becky vs Ronda for the RAW title, you can have Charlotte beat Asuka to get the title.
When Becky wins the Rumble, she gets the choice, and she demands both, in a winner take all match.
(Or it just make the choice more suspenseful)