A Snover set that I used successfully on several teams is a speedier, more annoying take on the Hail Support set:
Trait: Snow Warning
EVs: 4 Def / 252 SpA / 252 Spe
- Leech Seed
This set is obviously super odd looking, but I've found that it can be way more useful for my teams than the standard Eviolite sets. Even with Eviolite, Snover isn't going to be winning any Defensive awards, though certainly it does increase its bulk significantly. This set capitalizes on annoying your opponent. Minimum HP is used so that Leech Seed heals Snover for upwards of 18% against most enemies, meaning that between Substitute, Protect, and Leftovers, Snover will be healing more health than it is losing via using Substitute. Protect also makes Snover an interesting lead as it can scout out the sets of an opposing pokemon. If Victini uses V-Create, its generally a good bet that you are facing a Physical Victini and if Arcanine doesn't have leftovers, you know its an offensively based Arcanine. There are many more examples of its effectiveness as a Scout. Maximum Speed allows Snover to get the jump on Swampert, Bronzong, Blastoise, and everything with no speed investment under 80 Base Speed. This allows it to take out these pokemon one on one, as the combination of Substitute, Protect, and Leech Seed eventually stalls them to death or to very low health. Bronzong, something that plagues other sets, can be checked. Imagine the following scenario:
Snover uses Leech Seed
Bronzong uses Stealth Rock (predicting your switch because of the unfavorable match up)
Snover uses Substitute (its best to substitute in case they switch immediately, as you can then set up on the switch in)
Bronzong uses Gyro Ball
From there you can either Protect or Substitute to your heart's content. I'm not suggesting that Snover is a check to Bronzong midgame, just that it has more of an advantage over Bronzong than does the set already outlined. Snover has a great advantage over grass switch ins if it is behind a sub, because unlike other subseeder's, Snover can answer their switch with a super effective Blizzard.
Obviously this set has its downfalls, but I'd recommend trying it out before immediately rejecting it. This Snover isn't just a throw away spot; it can be used as a rather effective annoyer throughout the match. Having tested both sets thoroughly, I can say with confidence that I much prefer using this set and find it very viable.