customize xslt or customize the schema?

hi, I first posted this on docbook list; hopefully this is the appropriate place now. Sorry if you get duplicates...

Hi, I'm trying to decide how best to solve a problem I have with some tech documentation.
The doc is originally in LaTeX and I'm converting to DocBook 5 (using plasTeX). The doc contains both Figure and 'Output'  elements.
When rendered, a Figure is numbered as chapter.figure

The 'Output' element is like a  Figure, but appears only in Examples, and is numbered as chapter.example.output

There are of course references to both Figures and Outputs.

Which way should I go for this situation--add a new element by customizing the schema or customize the xsl stylesheets to use different numbering and gentext? I can differentiate between the two with xpath. (something like this: chapter//figure versus chapter/example/figure@remap=Output)

thanks for any insights.
--Tim Arnold