I would love to play with Allan, but I'd do it in my own way. I don't mind flailing badly, I would just want the experience!
I experience Mark as more of a pop bass player who has incorporated some of the flavors of jazz players into his music. Throwing him into the deep end of jazz wouldn't be fair. However, I've had the same thoughts about other players. I know that John Scofield played in Phil Lesh's band, but I'd love to hear it the other way 'round. Of course, he's got Steve Swallow on the job a lot, so that's sort of close. I hope, though, when I get into my 70s, that I'd be willing to stretch myself.