In any case (not in response to you, Rising Dusk, unless you've been in on the "the guessing game goes in favor of the attacker," I'm too lazy right now to see if you are), the guessing game could go in favor of either: Predict a Scizor, see Scarftran come in. Predict no switch, watch Scizor come in. Salamence would quickly be worn down and KO-able under those circumstances. Predict a Scarftran, see an enemy Mence. Yes, it can go the other way. However, I've found Mence to simply average being worth slightly more than it's slot.
As for the lure bit, yes, it works. However, the opponent might also not use Ground (Fire type: use Waterfall/Surf, Poison: not common enough, but likely, Rock/Steel: just attack a different type, though that might work. Fire attacks are a slight threat, though. Electric: Well, I just might fall for that, Hook, Line, and Sinker, but...)
However: Are the CRE 1500+ players using it in a broken way? By the way, Aura is a different username, already in use.
The statements three paragraphs previous is why I half-jokingly suggest a probability characteristic:
A Pokemon is Uber if, in normal battle conditions, it can force an opponent into a probability guess where the opponent has a 50% or greater chance of misguessing and being defeated because of the misguess.