Consider
(a) a throttles closed descent is very low thrust.
(b) all engines failed is a bit lower thrust ... bit higher ROD
(c) the rest of the aircraft's aerodynamics etc., probably doesn't know that all the engines have failed
(d) end result is a forced landing with higher keypoints and the pilot needs to be very attentive to energy management
We used to give students the typical 10,000ft somewhere near the airfield second failure on the 737-200/300/400 and there was no problem getting it on the runway in a tidy fashion.
What I found to be particularly interesting was that a wide range of techniques all worked fine .. provided that the pilot was attentive to the energy situation and stayed well ahead of the aircraft.
A significant number of folk didn't succeed the first or second time while they got their acts together ... however, once the problems had been identified it really wasn't any different to doing a forced landing in a C172 (except for the wheels thing).
Should be similar for other FAR 25 aircraft.