I just don’t see how the World Government will stand a chance, given that Whitebeard and his allies alone were pretty tough. And the fact that Luffy and his crew are getting stronger at a crazy rate despite having sailed for so little.
In the future, I suspect the following people/groups/nations that we currently know of to be temporary allies or members of Luffy’s fleet in this battle:
-Current Straw Hat Grand Fleet (Beautiful Pirates, Barto Club, Happo Navy, Ideo Pirates, Tonta Corps, New Giant Warrior Pirates, Yonta Maria Grand Fleet)
-Remnant Whitebeard Pirates and their allies
-Red Hair Pirates and their allies
-Warriors of Elbaf
-Wano and Kaido’s daughter Yamato
-Alabasta
-Kuja Pirates
-Katakuri and friends
-Dressrosa
-Dracule Mihawk
-Zou/Minks
-Crocodile and friends
-Fishman Island
-Sun Pirates
-Water 7 Allies
-Skypiean Allies
-The 11 Supernovas and all of their crews
-Revolutionary Army
-Buggy and friends
-Germa 66
-Rayleigh and remnant Roger Pirates
-SWORD members X- Drake and Koby. Plus, Garp and possibly Aokiji, Sengoku, Smoker and Fujitora.
To quote Mihawk, “It’s not a Devil Fruit, or some cheap trick… One by one, he turns the people around him into his allies. More than anyone else sailing the seas… That man possesses the most terrifying power.”