Have you tried making a tactical map version of the unit in question only with a smaller scale? It might mean making a new unit xml and copying the unit in question, renaming it, and changing the scale (plus adding the other needed pieces of making a new unit).

It's quite possible changing the unit scale only affects it's map size as well. Honestly I'm not sure. It would be cool if we could use this to make races like halflings and giants though without the need to make a new model for them.

I think making Dwarves is more complicated than just resizing the models. They should have different body proportions than humans.

<GrumpyOldManVoice>You kids these days are spoiled, that's what.  Why, back when I modded games all the graphics were .bmps once you decompiled them and then you'd edit 'em with MSPaint and like it, that's what you'd do!  Now you kids use your fancy 3D modeling tools and your XML and...hey, get off my lawn!</GrumpyOldManVoice>

...personally, I have a couple uses in mind for re-scaling units, although they'd also involve a couple other changes, but I'm interested to see how this turns out...