>>44834328>implying a random kid is justified in lore to get all the legendaries in a regionFor Hoenn in particular it makes more sense for Wallace and Steven to get the legendaries, because of Wallace's role as guardian of the Cave of Origin (and being able to reach the peak of Sky Pillar) and Steven's lifestyle in exploring mysterious caves and ruins to collect stones, on top of them being powerful trainers.
Though for Winona in particular, her only characterization is that she's obsessed with soaring the skies and that she has devotion and willpower that's unbreakable, so it's not that farfetched for her to have gone hunting for a sky legendary like Rayquaza