"Aerobatic" to me implies that you should be able to do spins and snap rolls, and stop them with reasonable accuracy. To do so you not only need a strong and effective rudder, but you also need a low "polar moment of inertia". In other words: All the heavy stuff needs to be as close to the CofG as possible.
With conventional twins you have two big lumps of weight reasonably far away from the CofG. That would make spinning, snapping and particularly the accurate recovery from those, well, interesting.
Bob Hoovers display is certainly interesting, but I don't think I've seen him do a spin or snap roll.