Certification performance has nothing to do with actual performance.
I totally agree. Many years ago, Nicosia departure on a hot day, British built three engined aircraft (can't mention the actual type) with water injection, having got airborne we climbed away at around 200ft/min. Took almost ten minutes to get to 2000 feet!
A week later at the end of two days on the sim we had finished early and that well known phrase "that's it gentlemen, anything else you would like to practise?" was uttered by the Training Captain.
I suggested we set up the sim for the Nicosia departure of a week earlier and complete the take-off. Once airborne, throttle the engines back to give 200 ft/min, noting the rpm's/thrust. Then complete the exercise again with an engine failure after V1 but setting the thrust levels recorded from the previous take-off on the two remaining engines.
Perhaps, realising the consequences of such an exercise the training captain declined the request.
"Head in the sand" approach? Stick to all the standard sim check exercises and ignore the real world? Most certainly yes!