If Davy D. Jones and Joyboy are different people, that would mean Jones was Joyboy's deuteragonist/rival
Their will were incarnated in Teach and Luffy
That would mean Luffy won't defeat Imu alone.
Teach and Luffy vs Imu
Like Naruto
And that means Luffy vs Teach will happen after Imu be defeated (like Naruto vs Sasuke after Kaguya)