The technique of the other pilot following up on the throttles (aka thrust levers) was to stop the things being vibrated back to the less than fully forward position with a subsequent loss of power. The flight engineer, if there was one, tended to do this.
Now that the big pistons have gone and we are stuck with these mamby-pamby limp-wristed jets we still do this and the other chap is able to fine tune the power whilst the pilot flying tries to keep the thing straight.
Naturally, for the non-luddites on the latest generation of aircraft the hands are there, once the required power has been cross checked,
simply to slam them shut should a change of heart be indicated.