I think a better way is to get 2 , 2 channel transmitters and 2 receivers per tank. I have tried that with a leopard in my club and it was a very fun way to get someone to start with the hobby. Not sure if 2 transmitters operating one receiver will have any issues as I have yet to tried that. In my days of flfing, even turning on the transmitter with the same frequency as someone else will cause teh model to freeze up.

I think in order to make what you described work, one will have to have both radios to be exactly the same make and configuration but I do not think it is easy to disable any channels in a transmitter.

Thus it will be easier to make a tank with 2 operators running off 2 seperate transmitters on 2 different frequencies and 2 receivers. Of course only the more spacious tanks can put 2 receivers or you can always use park flying receivers that are tiny.