The "staff" you mention that does the walk-around of the major commercial airliner is/are also the person(s) who will be piloting the plane, IIRC.
A plane lands, taxis to the gate. Passengers disembark, the plane gets cleaned and refueled, people on the ground checked it out, new passengers board (me), and it taxis from the gate. At no point did the pilots leave the airplane to "walk-around".