Considering the abundance of hitmontop and scizor, and how little Umbreon can actually do, I wouldn't recommend it...VGC is a very fast paced metagame, so in general pokemon that are purely support pokemon don't do well unless they can accomplish something important (i.e., speed control with TR, t wave, icy wind, stat boosting with helping hand or swagger, etc.)
I understand the urge to use non-standard pokemon, but unless it can do something really amazing and catch people off guard, it's probably not worth it. That doesn't mean you can't be creative of course...I mean look at Wolfe Glick's worlds team xD
But yeah, definitely check out the tutoring, I think you'll be surprised by how helpful it is. And good luck this year :)