Hey, I thought of some hints again. xD
-In Hoenn and Unova, the first stage of the fire-type starters does not have flames sprouting from there body, while the other regions' does.
-Both in B/W and R/S, you get the region's common birds late-ish in the game. eg; Pidove is found at Route 3 and Tailow is found in Petalburg Forest. Pidgey, Hoothoot, and Starly are both found early in there respective games.
Oh and if you talk to a lady at the counter inside the market in Driftveil, she mentions the herbs are imported from another region, could that mean they're from _______ town? (Forgot the name of the town, it's the one with the how springs and fire type gym leader.