Pioneer is video, Marantz is audioBoth the Pioneer and the Marantz are receivers. Why are you trying to connect two receivers to your TV?
The primary function of a receiver, by definition, is to provide audio output, usually of very high quality. Recently, recievers have been expanded to also handle video distribution but they still provide high quality audio output. I’ve looked at a photo of the back panel of your Pioneer model and it looks to me like it provides everything you need. I think your problem is that you’ve got a box in there that you don’t need - the Marantz.