Cattletruck:
Is it a single multi position switch - (OFF*)/FWD/AFT/BOTH
Or are they two separate switches - OFF/ON - for each XFR pump
As you say, a three way FWD/BOTH/AFT with a separate OFF elsewhere might increase your chances in normal operation of not inadvertently selecting them both off.
A mini-version of the fuel tank, in front of your eyes, filled with mercury and suitably wired, might save you the trouble of selecting/deselecting.
