The only reason you gave is simply that that arrangement was more convenient to set up on P9 (?). Personally, I really don't see how it can be more convenient to set up that way, which means, that, for me, there's really no good reason to have it setup like this.
However, I think I enumerated the reasons why different VMs make more sense.
Am I missing the point here? Possibly, but it's my opinion that this problem is 'exotic', as it shouldn't be encountered if you are setting up multiple versions OS X on Parallells the most efficient and easy way possible, which would be, different VMs.
Anyway, good luck with solving that problem.
Last edited by a moderator: Sep 5, 2014