Unupgraded, this deck would be two times slower. Even upgraded, the poison is too slow to take affect. Sure, if your lucky you can get 46 poison counters. But the chance of that happening is slim at best.
Sorry to shoot down your idea. It is a good one, but its too slow to be effective.
My suggestion:
Go rainbow (5 elements: gravity, life, aether, and other) and add Nightstalkers and deadly poison to it. That way, your getting 2 poison counters per scorpion. Combine that with the 46 poison counters from Scorpion, and you get a guaranteed win. (That is 138 poison counters, by the way.)