In a highly reliable industry it is difficult to assess safety from outcome - failures; we don’t know; and the important issue is ‘knowing what we don’t know’.
There are many factors which could be cited as contributing to modern safety, we cannot quantify them, more often because of human involvement - the human contribution.
The industry judges that CRM and SMS contribute to safety, but we are unable to explain why, thus we are reluctant to ‘ditch’ them. The most quantifiable safety improvement is from technology, where the latest systems appear more reliable than humans; but alternatively we don’t know how often (or how) humans saved the day - adjustments in normal operation.
Where monitored approaches are judged (not proven) to have equivalent safety to alternative procedures, then the advantages of wider experience for all crew members could be beneficial, but always dependent on context. With the very latest systems the least experienced pilot could fly and monitor a fail-op auto-land, experiencing the real visual conditions - placing the simulator in perspective, but still retaining the more experience pilot as an overall monitor. Correspondingly simulator training would focus using technology, and avoidance of adverse human involvement. (See Ziegler's views; BD99 thread in Safety, CRM, … )
Again, depends on context, it is not a universal answer.
The value of this type of thread is its subjective nature; many views and opinions, which if well argued, in context, provide valuable knowledge of airline and equipment operation;- what happens in everyday operations and a more meaningful view of safety.