Steering and quite a number of functions are controlled separately from the engine. The chances of a 100% survival rate without a skilled glider pilot at the helm is somewhere between slim and none.
I think Scully is also a glider pilot in his free time. The whole crew are heroes.
Oh BS.
The vast majority of commercial pilots can handle the job, it does not take a glider pilot.
Are you at all aware that nearly every descent in a jet is done at "flight idle", meaning there is little thrust from engines..in other words, they are "gliding" for portions of every flight?
The vast majority of engine-out emergencies end up well, providing they are able to find an obstacle-free area to land in.