>>149855438
Ash is wall level by his actual feats, man. Sometimes he manages to get as high as building tier, but that's uncommon and very usually done by his Megas or Z-Moves.
The birds don't destroy the islands by themselves, it's just that catching them and disrupting the balance of nature or whatever magically creates a storm that will destroy said islands. Also, wizard creating a storm with a spell can still be knocked out by Mike Tyson.