There exist various standards for splays but the skill matter remains critically important.
Many years ago, a local Regulatory certification/ops engineer (Ian C, if my recollection be correct) organised for a simulator study to be run with the two major domestics over here. Typically, a minimal briefing on the exercises he wasn't interested in .. and, I suspect, no mention of any engine failures. I note that Ian, for whatever reason, had missed out on getting into the airlines as a pilot ... but he was certainly a sufficiently experienced flyer to understand the significance of the study.
In amongst the distraction exercises, V1 failures were introduced and the subsequent flight paths tracked. I still have a report on the exercise tucked away somewheres and the graphed tracks are interesting, to say the least.
I don't recall the sample size but it was more than reasonable for drawing some inferences. While the great majority were fine, there was a fairly small number which indicated that the pilot flying was away doing something else at the time or, for whatever reason, just having a bad day ... it wouldn't have mattered what the splays were ..
Now this was with two airlines (in a commercially protected environment) both of which indulged in significant "over training" compared to what we see these days ...
Obviously there was some post study navel gazing to the airlines' benefit ...
... food for thought in our current minimalist training environments ?