Morning Mike, I see then you need x3 channels x1 for main steering on the front wheels the other x2 channels need to be on a mixer this is where the secondary steering comes in, in certain conditions you may need a little extra steering this can be done with the tracks mostly you won’t need this, for instance left stick forward/reverse drive and left/right steering through front wheels right stick left/right steering through the tracks.
All German halftracks steered through the front wheels and partial track breaking for sharper turns this was done through the steering wheel.