I can't see how we can discuss changing the Species Clause for Rotom or making it an exception and try not to discuss Shaymin, as the latter's formes have more differences between them than Rotom's except for "Rotom-Weak". We also have two Deoxys formes allowed in the mostly played tier and some (admittedly few) people believe at least one of them is broken, so allowing or disallowing both of them together would have a bigger impact than multiple Rotom as only Washer is OU. From the posts back in November, the main argument to keep them under Species Clause was exactly "ok why Rotom and not the other guys", so we are only going to settle this if we discuss all of them together.
I don't think we should even take Arceus into account as what makes it change its sprite+typing is the item it's holding. It seems to me it would be the same as treating Specsmence and CBMence as different pokémon. Same thing with Unown, as its only difference between formes besides the PID thing (lol seriously) is the sprite, and no way in hell we're going to let people use blue and green Salamence at the same time.
I agree that our Species Clause should allow alt. formes to be used on the same team, as they're pretty different on their own. None of them share the same base stats except for the five Rotom-App, and even then each of them have different typings in B/W.
I still feel the same regarding this and, after reading Eric's reply to my post, I'd like to suggest a new definition for Species Clause.
Our current one says:
Two or more of the same Pokémon may not be used on the same team.
I propose changing it to:
Two or more Pokémon with the same Dex number may not be used on the same team. If one of those Pokémon has different base stats or typing, and does not need a specific hold item to be used in battle, it will not count for Species Clause.
B/W Pokédex may show all the different sprites (shiny, male-female, backsprites, different formes) a pokémon has and we could say they are "different formes officially recognized by Game Freak", but they have no competitive relevance as mere sprites. So, with this new definition, we end up only with those formes officially recognized by Game Freak (such as Deoxys)
with a competitively relevant difference.
You may only use one Gastrodon because whether its sprite is blue or pink doesn't matter, it's going to wall Kyogre anyway; different Deoxys are allowed because they have different base stats; both Shaymin and Shaymin-S, or all Wormadam, are allowed together as they have different base stats
and typing; all Rotom can be used together as all of them have different typing. One of them has 440 BST, even! You can't use Meloetta-A and Meloetta-P at the same time, however, as you would have two Aria formes at first and
then would send out one to transform into Pirouette, and Species Clause specifically says they "may not be used on the same team". And I hope no one even dares mentioning frozen Shaymin-S because come the fuck on,
how do you freeze a 103/75/75 pokémon with a 4x weakness to Ice, and what would the benefit be?
The exception to this is Giratina as, while its formes have different base stats, its Origin forme can only be used holding a certain item; Giratina-A is more of a mere moveset variation than a "spin-off" pokémon, which makes it more similar to CB/LO Salamence, Damp/Drizzle Politoed or even DD/Pursuit Tyranitar, than to Shaymin/Shaymin-S (which, I'd like to add, also needs an item to change formes but it's only outside of battle so, again, no competitive relevance). Oh, and Arceus doesn't count because it's not officially recognized as having different formes~ And even if we do recognize as such (or if Game Freak now doesand no one told me), the item limitation still applies. It's even worse with Genesect, as the Drives only change its sprite a bit and also its signature move's type, which no one would ever use except if they want a weaker version of Surf to hit... something... super effectively.
Of course, all of this matters only if we want to use multiple Rotom or multiple Deoxys together. Keeping Species Clause as it is wouldn't make the game any worse.