c100driver,
Unless my company are doing "non-Boeing" (which I doubt) the FO merely commences the start sequence by selecting the start switch, for the rest of the start the Capt is expected to select start lever/monitor parameters etc. . . & steer the aircraft whilst responding to the driver of the Tana . . . . so, not so clever after all.
Personally, using these tugs I always waited till "Parking Brake Set & Goodbye" before doing anything involving engines. . .but , then again, I never did single engine taxi either (horrified to see Easy Jet doing it all the time on the Bus . . . hate it myself. )