What I've been told over the years:
Linda Rondstat wanted to do a live tour but had no band. She went to the LA musicians hall and put together a group to go on tour with her...after the tour, the tour band essentially became The Eagles.
Linda was a founding member of the music group Stone Poneys that included Bobby Kimball who went on to become lead singer for TOTO.
Here's an example of TOTO with Kimball as lead singer: Hold The Line
(By the way, Linda shacked up with Jerry Brown the first time he was governor of California. Jerry wouldn't live in the governors mansion.)
I didn’t know that about TOTO, love TOTO, big back in my younger days...
Yeah I remember Linda and Jerry being an item back yonder- Linda had such an incredible voice...
And Joe Walsh, wow, he was on death’s door prior to the Eagles come-back, they made him get sober and clean before the tour...Joe said, they saved his life....