Hoenn and Kanto have to be within a somewhat close proximity to each other because Navel Rock and Birth Island are accessible in both. So it's possible that the events of Groudon's awakening in Emerald caused the Volcano to erupt and destroy Cinnibar Island.
This isn't official, but it makes sense. http://serebii.net/pokearth/
The placement of Sinjoh Ruins makes no sense on this map. It's supposed to be partway between Johto and Sinnoh. This map has it on the opposite side of Johto from Sinnoh.
There's always, you know, this. http://static.fjcdn.com/large/pictures/59/44/59440f_1330130.jpg
(Yeah, I know the map of Hoenn is actually rotated 90 degrees counterclockwise.)
Also, FRLG specifically say that Hoenn is a long distance away from Kanto, so I doubt that Groudon had anything to do with Cinnabar. Entei is more likely (if any Pokemon is related to the incident) because of two things:
1. HGSS retconned the Legendary Beast incident. In GSC you awoke them, but in HGSS Eusine has already been on their trail for quite some time and has tracked them to the Burned Tower. This leaves room for point #2...
2. In FRLG, the three Beasts roam Kanto post-E4. So Entei has actually been shown to be in the Kanto region between the events of FRLG and HGSS.
I believe the beasts appearance in FRLG is canon, much like I believe the appearance of the Winged Mirages in Platinum is canon. (HGSS throws a kink in that second one, but I see the addition of the Mirages and Mewtwo as being non-canon since no one in-game actually mentions them.)
I like that map actually. And there are more than one of each of the Legendary Birds. Mewtwo is one of the only truly unique Legendaries in Pokemon canon. They could just be another group of them flying around Sinnoh.
Yeah, but then how would they invent new regions?
That's why I said "as we know it." They can add to it/alter it. I just want to know the relative distances and relations between the currently known regions.
White FC: 4727 7422 4019 Platinum FC: 2063 5286 9480