just find a custom deck that won't glitch with the current system, and practise for a while to check it works by itself.
there won't be "winning" decks until the AI can be customised or tuned to handle complex decision elements,
i.e. heal or create a taunt card, heal a taunt card to survive, use a booster when certain cards are available on the opposing team, etc.
you're at the mercy of whoever puts the AI together, because they decide what decisions are made, what play style is important, or wins rounds more often.
the other way to go is to create user profiles, but i doubt anyone will start or finish this.
if the AI learned to play each card, then you might have something both awesome or horrifyingly dumb. for now, it's just the latter.