>>39310334>>39311326The evolution levels of Gen 5 pokemon are based on when they were encountered in BW. So Hydreigon, Braviary, etc are like that due to their prevos being encountered at or near Victory Road.
Gamefreak was high on the idea of an entirely new roster 156 pokemon, so they decided that every route and area in BW would have at least one new pokemon all the way until the credits.
But they didn't want players to instantly evolve the prevos, so they set the evolution levels absurdly high to ensure that players would always have to spend time with the prevo first.
No, they did not consider that these pokemon might be encountered earlier in future games.
No, they did not adjust the evolution levels for said pokemon when they were encountered earlier in future games.
If you catch a Rufflet on the first island in Alola, you get to enjoy carrying around a base stage bird that won't evolve until the very end of the game thanks to its evo level being specifically set for its encounter in BW.
By the way, care for a sky battle with a sky trainer?