>>35840208Sinnoh wins by raw canon power of their legendaries.
Hoenn can psuedo compete because Mega Rayquaza and the Primals are ludicrously strong, and have stats (aka combat abilities) that exceed Sinnoh's legends, but including the canon of universal control, they're just outclassed in a war. Sinnoh's minor legends are also much stronger and more numerous than Hoenn's.
Unova probably has the next best shot due to raw legendary and general Pokemon count, including access to fused Kyurem, but again falls short to total universal control.
A more interesting discussion might be who's first to be eliminated.
Kanto offers nothing exceptional outside of transformers and Mewtwo, putting it pretty low on the spectrum, but it does have a large army due to its 151 dex size, so there's a possibility it's not worthless.
Johto gets a bunch of evolved forms for Gen 1 Pokemon, but it's own regional options are abysmal outside of Ho-oh, which is too little by itself to make any real ground against regions with armies of legendaries.
Kalos' legendaries and Alola's ultra beast's probably are big enough to keep them in the running over Kanto or Johto.
