I like to use these radios
click it to run an excavator. You see the sliders between the sticks, with the mixes built into many dual esc's, one slider would control for/rev and the other slider is for turning lft/rht.
You could also use two dials for track movements, if that is what the radio has.
I wouldn't recommend 3 pos switches b/c you're either full on or off, it could make model movement a little harry when finese is essential, like driving onto a lowboy.
Six chs for the basics: boom, stick, bucket, swing on the stick controls, with tracks on other proportional chs. You might want another ch for a thumb? Or lights?
I think Servonaut has an electrical device where you can turn off signal to one model, then turn on another to use same radio. All constr models I have have their own radio, while five trks are tuned into the same two radios.