I believe that the mentorship program in the IW community is broken because of the lack of oversight and dilution of leadership.
On subs and surface ships, the leadership is held accountable for their subordinates' deliverables, and therefore it is in their best interest that the deliverables are produced at a high quality. While this counts as training, it also builds trust and establishes regular contact which facilitates incremental mentorship. Also, wardrooms on ships smaller than CVNs encourage the eating of meals with the CO and below. This, again, facilitates mentorship at mealtime.
The IW community is too diluted at all levels. Regular contact with the CO at a magnet site is impossible, department heads are often in different buildings, and rarely do they provide oversight on any deliverable other than a random slide or blurb about the weekly activities within their subordinate divisions. And I concur that on ships, being 1 of 1 doesn't help developing IWs as IWs.
I'm all about mentorship dialogue, but the unfortunate thing is that those that need it the most are the ones who tend to not seek it out. So whatever mechanism is selected for the "final answer" needs to address these outliers (which in my experience is actually about 75% of the new ENS/LTJG 1810s I've met).
One suggestion: engage with C10F or IDFOR to provide some kind of structured oversight (a la URL communities). Through the execution of the assigned tasks and / or in preparation for inspection, those officers will seek out mentorship out of necessity. This is the painful answer, but the only one that will last in my opinion.