I don’t think there’s any way Garp is winning and leaving the island. It just doesn’t make sense narratively for him to stroll into Pirate Island and leave clean.

But Koby has to escape. I think there are three options:

• Garp gets up, gets Koby and Grus to safety but is defeated in the process
• Smoker shows up finally answering the question of what he has been doing for the last decade or so. He’s able to rescue Koby and Grus and Garp either leaves but is critically injured or he doesn’t leave
• Bogard jumps from the ship and backs them up, allowing Koby and Grus to escape