Ozex youll find most 737 sims dont simulate (at least the ones Ive been in) an engine fire that ends up with the fire catchin the tanks or the engine burning itself off the wing and severin fuel and hyd lines and maybe takin the bloodey wing with it. ALL real possibilitys esp with an uncontrolable fire.
Unfortunatley 99.9 pc of engine fire/failure exercises conducted in the box mate are PROCEDURAL checks only. That is, a check of the pilot's standard for that emergency and that adherance to checklists etc have been carried out. Its all done relatively calmly. Real life could have complications such as ATC confusion, ATC freq congestion, a crew-member freezing up (it happens!), severe turbulance, secondary emergencys such as contaminated cabin air, and a panicky cabin about to riot if the pax can see flames under the wing.
An engine fire is a deadley serious affair (just ask any surviving ex-Viscount 700 driver) even in these sophisticated modern jet aircraft with more reliable engines. I believe it should be part of the overall training to be aware of the subsequences to uncontroled engine fires and yep, actualy simulate what COULD happen.