multiple teams retiring a player's number...

He only pitched in ~10 games for the Expos. Retiring his number wouldn't make much sense. With the Mariners he put up three or four great seasons, but there weren't many other accomplishments (as a franchise) during that time, so the case is pretty weak.

I'd say two situations warrant number retirement - a long good or better career primarily with a single team (face of the franchise stuff), or leading a team to the World Series or something over a shorter amount of time.

Clemens had resurrected his career in Toronto with two strong seasons, but I don't think they even made the playoffs those years. That's a definite no.

Unit - Montreal - no, Seattle - maybe, Houston - no, Zona - yes, Yanquis - they've run out anyway

Don't forget the one time Unit wore a Giant's cap.

The Milwaukee Brewers retired Hank Aaron's #44, but I would assume that is for his great years playing in Milwaukee for the Braves than the two seasons at the end of his career.

The M's had their first playoff appearance as a team with the Unit. Remember how bad they used to be back in the 80s, all that changed when the Kid and the Unit showed up. Remember that crazy tight playoff series where it was pretty much The Unit and The Kid versus the Yanks and they almost won? I think Johnson started three games of a five game series, after pitching every third day down the stretch to get them into the playoffs. There was some good things that happened in Seattle when Johnson was there. He still probably deserves to have the D-backs logo on the hat, being the MVP of a World Series and all.

i guess in my mind the line kind of gets blurred b/w retiring a player's name and electing a player to a team's hall of fame, where there hurdle seems to be lower. the team hall of fame seems to have more fan favorites, but retiring the number is maybe more for the universally regarded player? i dunno...something like that.

That's not so surprising -- in any given era, there should be about 30 future HOF's playing the game, so not every club will have one, some will have more than one, etc.

Seattle and Arizona are relatively new franchises who need/want to create history, so I think Unit is a lock to have his numbers retired in both cases. As noted on this thread, he had several great seasons for both clubs, winning a division title with Seattle (their first, and along with Edgar and Griffey, turned them from the biggest joke in baseball into a successful franchise) and the WS with Arizona.