I've been under the impression that Glaceon's ability to blizzard right through resists is one of the biggest reasons why Glaceon is considered broken at all. Its power can be considered overkill against pokemon that normally get OHKO'd by blizzard anyway, but I'm talking about Glaceon's ability to unconditionally 2hko most of the tier, which Jynx and Rotom-F are less capable of doing. It's not overkill because the power is needed. Also, it's true that Jynx and Rotom-F have about the same number of viable movesets as Glaceon, but I feel that Glaceon's variety within its movesets gives it a more threatening presence. Glaceon has the ability to bluff choice between Scarf and Specs, with one that out-speeds nearly all of the un-boosted metagame while the other one just demolishes everything, and with Specs it can make great use of Trick Room support. Imo running Specs on Rotom-F and Jynx would only be good for the surprise factor, because it wastes their potential and they can easily be forced out, KO'd and/or worn down by hazards. The "third" notable Glaceon set is one that scares out an opponent and subs on the switch. Glaceon behind a sub is an incredibly destructive force considering its ability to stall out entire teams and outright KO most things that are resistant to Stallrein tactics. Compared to Jynx and Rotom-F behind a sub, Glaceon is far more threatening in this respect. Non-scarfed Jynx almost always runs Lovely Kiss, which means a Jynx behind a sub will either be mono-attacking with blizzard and Nasty Plot or Blizzard and a coverage move (honestly i dont think Psychic does Jynx many favors). Sub-split Rotom-F is also less threatening than Glaceon behind a Sub. It can grab a couple kills at best. The same could be said about any hyper offensive attacker in RU that comes in at the right moment.