Pokemon, what happened to you?

[JarJar]

4 starts during 2, as the Red Gyarados problem begins.

I thought that too, but Lake of Rage has a ton of Gyarados in it, and since red Gyarados is his shiny color, it could just be another one. If anything, 2 is a little after 4 because I remember reading somewhere that in HG/SS's Arceus event, you see Cynthia and she states that she was the Pokemon champion. If this is true then that means that it would take place a bit after 4.

this is not likely at all, if cynthia states she was champion then it would be BEFORE 4 since you become champ AFTER that. and another red gyarados? thats just dumb, the red gyarados got his color because team rocket used a radio signal that alternated his color, seeing a simple shiny and not referencing that (along with the other shitload of gen 2 references in dppt) would be silly.

sinnoh is the last region as of right now in terms of ingame timeline.