Thankyou- said far more eloquently than I could! I have 18 years on all models 747 except -300, from 1977 when engine failures were 'not unusual'. At that time, I had approximately half a dozen IFSDs for various reasons, mostly unrecoverable surges. Never with a problem that extended further to other engines.
We have to be careful we don't go striving for academic statistical nuances here, rather stick to practical experience. Incidents such as El Al/AMS double IFSD are exceedingly rare. I believe it right to say that a large proportion of double IFSDs can be actually put down to shutting fuel off on the wrong engine. As stated, nice to still have 2 left rather than 1, even if the T/W ratio is very slightly poorer!
Having said all that, bottom line considerations (and A340 experience) confirm that the 4 engine jet cannot compete with widebody twins (like that nasty common, but bloody efficient 777). They are now dinosaurs, but re-assuring dinosaurs!