Fair warning, this is probably a ridiculous idea because I'm nothing close to a mechanical/aerospace engineer.

Would it be possible to mount the ramjets to a ring around the blades along with some sort of transmission in the ring? I'm thinking setup this would allow the ramjets to function supersonically at the edge of the structure to ensure the best airflow and limit the speed of the blades. However such a transmission might be overly complex or heavy and it's possible that the ring around the blades would cause some weird aerodynamic effects.

Thanks for obliging my curiosity!