The simple answer to why people throw the Mandos into things with Obi-Wan is Satine. Which we've never remotely gotten the appeal of, ourselves. Siri was a better love interest, to us. And if you want to give Obi-Wan a backstory involving war, Melida/Daan is right there.
(...need to finish up the Death Star section so we can get around to posting that Exile (and company) to OT story. Yeah, Canderous being there is going to involve the Mandos by default, but he quite literally comes from a different time so there's that. He's also just one character in comparison to the Jedi.)