In case you didn't know, (I'm pretty sure) our policy is that, when a Pokemon requires interacting with another player to obtain, we don't lower the tier because of the requirement; we assume that the player can interact with other players and tier the Pokemon as such. Thus, Spiritomb is tiered just like any other Pokemon that requires ten minutes to obtain, except that it's listed with a "(yes trade)" tag.I had this exact conversation last week.
I really think you're exaggerating the "10 minutes to obtain" part about Spiritomb. I really can't imagine someone finding 32 people in the underground in just 10 minutes. I know you can use the same person over and over again, but you have to resurface and go back underground again (launching DS wireless connections each time). That's got to slow you down quite a bit (and from what I remember, I never found that many people that quickly)
I'm pretty sure we're not allowed to tier Pokemon that require "extra stuff" to obtain. If you think about it, using a GBA cartridge to get a Pokemon isn't that different from using third-party software to edit the Pokemon into the game.
There's a big difference between using software (i.e. hacking) to get pokemon and using devices and features Game Freak designed to get pokemon. I've used the GBA slot to get pokes before because I grew up with the Gen 3 games and owned them all plus a DS Lite, so it's definitely a legit method. Although I will admit that we prob shouldn't tier those pokes because they are all postgame (making them useless), plus we can't guarantee what devices people are using to play (I believe the DSi doesn't have a GBA slot, yet DS & DS Lite do; and people may be using an emulator)