Hi Brian --
Sometimes you can, sometimes you can't.
I've tried recreating MOX voices on S950/Genos and I've tried recreating S950 voices on the MOX. If the raw waveforms are available, that's a good start. If the PSR/Genos articulations fit the Expanded Articulation paradigm, then you have a shot at it.
SArt2 voices, as a class, cannot be fully recreated on Montage/Motif/MOX. SArt2 (Articulation Element Modeling) does a lot of stuff that's not handled in Expanded Articulation and Montage/Motif/MOX do not have a synthesis engine nor the samples required to do AEM synthesis.
But, please don't be discouraged! I learn a lot by trying to cross-port voices. It's a great way to learn about a synth in depth.
All the best -- pj