You only need a certain amount of power in drifting. Since the tires have already broken traction, you're not putting more power to the ground when you give it more throttle. You're really just accelerating the wheels. When you have enough power to put the wheels at whatever RPM you need, there's no point in having any more power. Since power like that usually comes at a price, it can be difficult to find balance.
When you think about it that way, sims, slicks, or super softs, it makes no difference.