Larry Gives An Excellent Account...

 ... of Prigozhin's spiteful mind and where his hatred for Shoigu and Gerasimov originated from. 

Prigozhin is the business CEO of Wagner. He has zero military experience but is an established contractor, just like Raytheon or General Dynamics in the United States. He handled (or mishandled) the money flowing to Wagner and probably spread the wealth among some commanders. The cash flow from Wagner added to Prigozhin’s wealth. It also fed his ego and provided him the illusion of being viewed in Russia an important military figure. Fourth, Prigozhin reportedly cut a deal in 2018 with a Syrian war lord to capture a Conoco oil field in a portion of Kurd controlled territory, which was defended by a small group of U.S. Special Operations Forces. This was the Battle of Khashsam aka the Battle of Conoco:

In the end, those killed by USAF died for Prigozhin ambition and greed. Likely not only his alone. Rumor has it that it was either Shoigu or Gerasimov who after the event conveyed the message to Prigozhin to the effect that he should abandon stupid efforts to become Napoleon (or similar in scale leader) and that people died because of his ego and greed. Read the whole thing at Larry's blog. In other words, in case of Prigozhin you can take a man out of prison, you can not take the prison out of man.