Rampardos is fine where it is. Too strong for UU, but not a popular attraction.
On the other hand Rain Dancers, Sunny Day users function alot better when the extent of their fears is dealing with a Hippo baby and Snover.
In all honesty even if your that desperate your doing yourself more damage than you're doing favours. Your essentially running only 5 pokemon. I mean seriously Snover is the freakin equivilent of Farfetch'd in stats.
However, the vast majority of arguments for Glaceon and Walrein's place in UU was that their OU sets (Stallrein and Specs Blizzard) are impossible due to the lack of everlasting hail.
If Snover is in UU or below, then that nullifies most arguments against Glaceon and Walrein's BL status. That means stallrein
IS viable.
Now, if Glaceon and Walrein are moved up to BL because of Snover (aka, snow warning), then we can clearly see a problem. We are losing 2 potential pokemon in a metagame just so that one pokemon (snover) can exist, and no one is going to fricken use snover anyway. I'd rather ban snover and be able to play with Glaceon and Walrein in UU. Hell, maybe snow warning is the push needed to make Lapras a BL pokemon as well. It already boasts dragon dance, curse + Ice Shard, Bolt/Blizzard/Surf, 101 subs (with only 12 EV investment >_> WTF at 130 base HP ) water immunity, rest/sleep talk and more. And forcing the opponent to have no leftovers is pretty sick.
Anyway, I ask: what counters stallrein in UU? Hitmonlee's High Jump Kick will miss on protect making it kill itself >_> Close Combat from Choice Band Pinsir is still only a solid 2-hit KO, and it is not like Pinsir will be able to counter Stallrein, it only prevents it from setting up. Meaning I can easily just throw down a pinsir counter, then throw out stallrein against whatever other guy you sent out.
Even weird stuff like Whirlwind Crobat will die to Blizzard, so that isn't even a complete counter. Slower phazers can be roared out as Walrein's base 65 speed is not that bad, especially in UU.
The list of counters is small with Stallrein. I mean, its like Whirlwind Crobat and Roar Manetric that can actually force it out, but even then you'll have to deal with it later, and you can't set-up as Stallrein is also a phazer. Taunt/Plot Crobat is 3-hit KOed by Surf and OHKOed by Blizzard if you include hail.
And thats IF Crobat makes it to UU.
Basically: It does not matter if you are running only 5 pokemon when the list of 1 pokemon's counters is very small. That is what you call over centralizing the metagame.