One YN622C on my camera.
One YN622c on my YN656EXIII.
Two YN600EXRTII triggered by the YN622C on my camera.
Would I be able to do that...?
No. The Yongnuo 622 2.4 GHz triggering system is incompatible with the Canon RT system Yongnuo's cloned for their RT gear. To use a YN-622C or YN-622-TX as your on-camera transmitter, the YN-600EX-RT flashes would ...