Jon Favreau and Kevin Smith
I watched a few episodes of Dinner for Five on YouTube, good show btw, and I couldn't believe how much of a blowhard Kevin Smith was towards Jon. Interjecting, correcting and calling Jon out about how he can't stop talking about his first big movie ("Swingers") which is ironic because Kevin keeps revisiting Clerks in conversation as well. Clearly these two strong personalities clashed and they're both guys who talk a lot, except that Kevin is way more arrogant than he should be given his body of work.
Fast forward 10 years later and Jon Favreau is clearly killing it: he helped mastermind the lynchpin movie for the MCU Iron Man. That is huge, it's monumental. Iron Man (2008) is what BvS is to DC. So many big things depend on it and Jon nailed it.
And now Jon seems to be doing the same with The Jungle Book.
Meanwhile Kevin Smith seems to be making more and more movies that nobody watches. His last big movie was, arguably, Zack and Miri (2008). Same year that Jon put out Iron Man.