>>36497182The Great Marsh isn't a man-made reserve like the Safari Zone, it's a natural ecosystem that just has man-made transport and conservation structures. Pokemon within the Great Marsh are Natives, unlike most Pokes in the various Safari Zones.
Also iirc Dratini is implicitly native to the Safari Zone in Kanto, it is literally never mentioned anywhere in the Fuchsia Zoo area or otherwise implied to have been added to the Safari Zone and nobody knows it's there.
gen 2 mons that appear in Gen 2 Kanto could have simply migrated over there due to the cross-contact between the regions over the years between Gen 1 and 2 so they might have once been native to Johto proper.
Baby mons appearing in later gens that need a certain incense to be bred does not indicate that their later evolutions are only native to the later region. Those babies are effectively mutations; Munchlaxes can't be found in Kanto for example but there are still clearly breeding populations of Snorlaxes in Kanto.
