When comparing food processor models, why do some have additional blades? What are advantages or disadvantages to a middle blade in the food processor? Might this shape be harder to clean than a single-blade model?
It's also called top blades:
The Robot Coupe is widely regarded as the standard food processor for professional use.  Neither it, nor the industry-leading Cuisinart or KitchenAid food processors have those middle blades.  As such, it seems unlikely that they are requirements for a quality unit.