Ok, so your saying at worst the monk will be "slightly bigger" ?
I don't see how that could possibly pose any problem at all, are you implying that everyone of your figures has to be exactly the same height and girth ?
If not then what is the problem with having a slightly taller or "bigger" monk ? Surely there should be figures of all shapes and sizes if you want to create a realisitic display that will reflect reallity. The variation will only add to the display IMO, but I guess everyone sees things differently.
I still think it would really add to your display and is a really good Idea.