A) kinda hard to draft someone who is already a marine, when he left the marine he was branded a criminal, kinda hard to draft someone who is a known criminal

B) the forcing is just the idea that if you refuse the draft you’ll be an enemy of the world government. When Aokiji fought akainu, he immediately became an enemy of the world government and thus that threat is meaningless to him

C) basically the same reason no major pirate has been seen getting drafted into the navy. Forcing them to join would be more expensive than they would be beneficial. The risks outweigh the gains.

D) having your enemy forced to work for you increases the likelihood they’ll turn on you. Like hydra being inside shield if you’re familiar with captain america movies

E) fujitora and green bull may have been reluctant to become marines, but it certainly doesnt seem like they’re fighting the role. Fuji seems pretty content to pursue his own interests as an admiral