Bit of personal experience here but Sneasel most definitely can't do what Weavile can. Its attack is way too low to run any set beyond Subpunch or Swords Dance even with its double STAB. Pilloswine doesn't enjoy the 130 attack or 80 speed which causes it to come short on alot of things with a CBset. Yanma prefers to be more physical orientated in UU.
Just one question, is this D/P UU experience you are speaking of, or ADV UU? Because I find it hard to believe you've managed to get away with using those Pokemon on a regular basis in the current UU environment.
In the case of Yanma, I understand that going physical was likely the better option back in ADV, but D/P gave it two powerful special STABs to compliment its slightly better special attack, which are far superior to anything it can do physically. Sure, it now has U-Turn and physical Pursuit to go with Reversal, but those have more situational uses rather than all out attacking. IMO Yanma is likely to be at the very most running a mixed set in UU with Reversal along with its two special STABs to take on Steels, possibly utilizing Focus Sash and Speed Boost in the process, which would certainly be something different to what Yanmega does in OU. I was just using it as an example to emphasize the points made on both sides of the debate.
As for Piloswine, despite the significant loss in Attack and speed, I still see physical attacking being the best it can muster in lower tiers, and is still capable of hurting things with the Ice/Ground STAB combo, including Ice Shard that doesn't care about the speed drop. I can hardly see it suddenly relying more on its largely unchanged defenses and becoming a support Pokemon with PHazing, pseudopassing and what not.
Finally, in Sneasel's case I am aware that it isn't as powerful as Weavile by some margin, and also that it doesn't get Night Slash, but the fact remains that apart from the SD set, Weavile's primary role in OU is as a CB revenge killer to take out problem Ghosts/Psychics and otherwise frail pokes, something Sneasel is still more than capable of doing in UU at least.
For example, say someone was using Sneasel and, lol, Diglett alongside Facade/U-Turn Swellow to try and set up a Facade sweep. Despite the fact that these Pokemon are much weaker than their fully evolved versions, laughably so in the case of Diglett, they are still likely to be most effective at performing the exact same strategy in the lower tiers, which would probably irritate some people opposed to NFEs as they don't want to be subjected to those same old strategies for the purposes of fun.
Again though, I'm not on any particular side of this debate, I'll go along with whatever is agreed, I'm just trying to put each side of the argument into a clearer perspective.
@Darkflagrance, most of the points you are making are valid ones, I agree, but the fact there is still huge controversy surrounding this debate signals to me that it is currently standing in the way of progress in terms of implementing a new tier. Therefore it makes sense to me to just put the NFE argument to one side for now because the no NFEs rule has always been in effect until recently, and so people are familiar with the concept, thus the onus is on those supporting NFEs to prove their point, not the other way around.
Given the current situation, why can't we just concentrate on all the fresh, exciting and obscure Pokemon that don't see much use, i.e. BL/UU, for now and come back to this issue later? Are you so stubborn that you're preparing to let this drag on for months to no avail when we could just get straight into the fun part, the battling?