I doubt it. The PC terminal is "dumb", it only carries the signal to fire. I'm pretty sure the Canon transmitters expect more communication from the camera than that. Even if it worked, you would not have any of the control capabilities get with a Canon transmitter mounted in the hotshoe.
Instead, if you want a blended system like that, you have a couple of options. You could use the RT set up in the hot shoe, and connect a dumb wireless trigger system (Cactus, etc.) to the PC terminal, with wireless receivers for the non-RT flashes. Alternatively, you could get Sonia (green) optical slave triggers for the non-RT flashes. Either way, you would need to set the power on the non-RT flashes manually, the difference would be optical versus dumb radio triggering.
If you can afford it, go all in for the RT system, it's truly excellent.