Hypothetically, Luffy goes to Hachinosu to save Garp and is captured by the BB Pirates. He makes a deal to deliver both Garp and Luffy to the WG and if the trade is successful he will become a Celestial Dragon. BB arrives at the Holy Land to hand over the captives but right before the trade the following characters show up to save the Luffy:
The Strawhat Pirates & The Grand Fleet - Obviously to save their captain
The Revolutionary Army - Sabo forces Dragon
The Red Haired Pirates - To stop Black Beard from achieving his goal.
Marco & the Wano Crew
They are up against:
The Gorosei
Admirals
BB Pirates
A shit ton of fodder
Scenario 1: Luffy doesn’t get free unless they win
Scenario 2: Luffy gets free and can help
Can the pirates and revolutionaries save Luffy?
The Strawhat Pirates & The Grand Fleet - Obviously to save their captain
The Revolutionary Army - Sabo forces Dragon
The Red Haired Pirates - To stop Black Beard from achieving his goal.
Marco & the Wano Crew
They are up against:
The Gorosei
Admirals
BB Pirates
A shit ton of fodder
Scenario 1: Luffy doesn’t get free unless they win
Scenario 2: Luffy gets free and can help
Can the pirates and revolutionaries save Luffy?