Depends how Phase One and Mamiya see the future. If Phase One see themselves being marginalised by Hassy, Mamiya would look like a good partner. On the other hand, if Mamiya, with their new digotal division, want to mimic Hassy (the ZD back is I think for mamiya bodies only) then Phase could have real problems as options begin the shut down for them.
For Formula 1 racing fans, think of the Williams F1 team, who once doiminated formula 1 but who have become increasingly marginalised now their recent partnership with BMW engines has expired and Cosworth are off the scene. Phase are like Williams, dependent on their "partners" for survival at the moment.