George,
It's quite possible to have a File and a Program with the same implementation name on the IBM i, so it has to at least be catered for within Plex.
I was quite surprised that you could assign the same implementation name to a Table and a View, they are resolved to the same Object Type, so that is not possible (within the same Schema/Library). Then again, it is still possible to have the PF/LF reside in a different library, so I guess there is a need to cater for that?
It looks like the validation check is made at the Object Type level, which seems reasonable (bar the Table/View example). I was able to see the same behavior at Plex 7.1...
Crispin.