Kerr Neilson at Platinum (PTM) when he was more hands on used to write some really good stuff every 6 months in their shareholder reviews.  

See here:  https://www.livewiremarkets.com/wires/15-cracking-quotes-from-kerr-neilson

And:  https://www.platinum.com.au/Insights-Tools/Investment-Fundamentals/Investing-What-Matters/Article-Item/Interview-with-Kerr-Neilson

David Bryant, the MD of RFM and Rural Funds Group (ASX: RFF) always has some very insightful stuff to share - see here:  https://ruralfunds.com.au/rural-funds-group/investor-information/key-documents/   [look for their newsletters which come out around every 6 months, most recent one was the December 2020 newsletter - link below]

A great example:  https://ruralfunds.com.au/rural-funds-group/wp-content/uploads/sites/3/2020/12/Newsletter-final.pdf   [particularly "A world going nuts" starting on page 4]

Steve Johnson, the founder of and CIO (chief investment officer) at Forager Funds (ASX: FOR) is always very frank and honest about their wins and their mistakes.  And what they have learned from both.  See Forager Blog - A Value Investing Blog - Forager Funds

He also provides some very interesting insights into a lot of stuff, including the Gamestop Saga and a few years ago (Oct 2015), a brilliant piece called, "Dick Smith is the Greatest Private Equity Heist of All Time" by Matt Ryan, who worked for Forager at the time, which gave a very entertaining insight into how Private Equity groups often/usually operate and exactly how they scammed everybody with the Dick Smith float and subsequent collapse.

For a great insight into the minds of some of the best CEOs around in 2010-2012 (some of them are still running the same companies today actually), I found "Master CEOs: Insights from Australia's Leading CEOs by Matthew Kidman and Alex Feher to be a very good read.  Kidman was working for Geoff Wilson at WAM Funds when he wrote that, and he's now running his own fund called Centennial Asset Management.  My favourite CEO from that book was Graham "Scroo" Turner from Flight Centre who I have always regarded as a straight shooter and interesting guy to listen to.

I'd say that hunch would be a pretty good one Cigarbutt.  I forgot to mention Hamish Douglass who is the CIO (chief investment officer) of the various funds run by Magellan Financial Group (ASX: MFG) here in Australia.  I've invested in two of those funds for my kids, MGF (used to be MGG) and MHH, their high conviction fund, which has less companies in the portfolio, so higher weightings to the ones they hold.  If you ever get the chance to attend one of the Magellan roadshows, I highly recommend it.  Not only is Hamish absolutely worth listening to, he always wheels out a special guest who is also worth listening to.  I'm not sure if she still is now - since being appointed the US Secretary of the Treasury by Joe Biden in January - but Janet Yellen was on a retainer with Hamish, to provide him with advice and information, along with dozens of other high profile people who have held important strategic roles in the past and have a wide network of current contacts.  Yellen of course previously served as the 15th chair of the Federal Reserve from 2014 to 2018.  Another one is Michael Morell, a former deputy director of the Central Intelligence Agency (CIA) from 2010 to 2013 who twice served as its acting director.  Morell was the special guest at "The Great Repression" Magellan roadshow I attended last year, and he was good value indeed.  

Check this lot out:  https://www.youtube.com/channel/UCW1BNks78tbQyO426KNpBxQ?feature=emb_ch_name_ex

Particularly this one:  Hamish Douglass:  Knowing What You Don't Know (15-Jul-2020)

I think the best way to describe Hamish Douglass is (and I've said this plenty of times before about him) - he's always the smartest guy in the room.  He always appears to be anyway.  Well worth listening to.