This comes off a little negative but totally get the desire to show a sibling something different,as someone who uses to listen to rogan regularly...
Find whatever guests he liked and nail down what it is he's actually interested in. For me it was history and comedy.
History of Rome with Mike Duncan then lead to youtubers like sandrhomanhistory and the operations room. If he's into more military and masculine show him forgotten weapons also on YouTube.
If you go as left mainstream as John Oliver it's gonna be an uphill battle. Even though I more than likely agree with what he would say have 0 desire to watch it.
Comedy wise the early cumtown episodes are goofy classics.