Bit of headcanon, but I think the reason why the Indian and Spanish Pirate Lord both were willing to fight the British is because Jack's relation with the Indians might be good because in the deleted scene, it was mentioned he freed slaves, and the Spanish, welp, the Spanish overall got beef i think
Just finished rewatching the original trilogy again yesterday, and just have to share some appreciation for the masterpiece that it is. The Curse of the Black Pearl is the perfect beginning, Dead Man's Chest is an amazing follow-up and it's conclusion in At World's End is just perfect. GOAT trilogy.