I believe only one of them, Tim Smith, plays with Sheryl.  Also, Smith was the only Jellyfish alumni in Umajets, although both Roger Manning and Eric Dover appeared on the first album as guests.  The second Umajets member, Rob "Something," did not play in Jellyfish. 

I would guess that Tim Smith is the purported Elliot Smith lookalike.

By the way, the review Kravitz posted seems like so much BS to me.  And as a big fan of the late KG, I'm certainly not pre-disposed to defend Sheryl Crow.