Critical is ok. You have a point, it is far from optimized, but provided as an example of where to start. Keep the frontal area to a minimum, keep the airflow as clean and useful as possible.

Compaired to a Whiplash or diamond dust, or a QM40 for that matter.... the Phenom design at least paid attention to cleaning up airflow over the engine.

Even most of the guys flying speed cup could do a bunch more to optimize.