That place even has its own timeline theory. One that I don't really agree with.
I still think all of the games, with the exception of YI, YI2, YS, PiT(past), and SMRPG, go in the order of their release.
I think SMRPG takes place later on in the timeline because I've heard that Mario and Peach get married at the end (Yay!). In later RPGs, we see that Mario lives with Luigi. Even though they were released after SMRPG, I think those events happen before SMRPG. Wouldn't you think Mario would be living with Peach in the castle after the events of SMRPG? If I'm way off, it's not my fault my parents wouldn't let me get any video games till I was 12 or 13, and that Square still hasn't ported SMRPG to the GBA or DS. I'm only going by what I've read on the Internet.
Hmmm Actually, I think my bro-in-law might have SMRPG. Maybe I could ask him to lend me his SNES and SMRPG.