maybe the OP should set up a poll to make things easier?
the question asked is basically the old renaissance paragone of disegnio vs colore transferred to miniatures
http://www.oxfordartonline.com/public/page/benz/themes/Renaissance2also the science of painting in this article about Leonardo
http://www.britannica.com/EBchecked/topic/336408/Leonardo-da-Vinciwith the small difference that they are not arbitrary but sequenced in that the sculpting (principal outline) comes first and determines by far the coloration
so, let's see... artistic expression
is restricted in sculpting by the scale and norms of acceptable proportions as related to the subject
is restricted in miniature painting by the sculpting mainly and by a little amount of context (historical accuracy, fictional design)
so basically both are somehow context restricted, whereas the one depends of the other by a very large amount.
So I would concede that in terms of restriction, the relevance is debatable, whereas methodically, the question is obsolete given that there is no painting without sculpting.....
as to the digression about the artistry of miniature painting....
well, I will be the last one to contest that there are a few participants in the hobby who can be regarded as artists, these contributing in the sculpting department mainly; not so many in the painting department. Interestingly if I were to name someone (IMHO), the colour control (Captain Blood) and the tonality control (Blackwolf) come to mind, and it is remarkable that both also excel in sculpting and scenic design, disciplines beyond painting alone. So if I were to use these two examples as proof for artistry in miniature painting, I would claim that it would be the artistic approach and not the painting per se that qualifies them for this distinction. That said, please take this argumentative sketching of mine for my claim that the painting of sculptures of any kind is (almost) never art, but craftsmanship of (quite often) the best quality.
Plus, I always get suspicious when people blow their own trumpet too loudly... It tends to be self aggrandizing rather than reasonable reflection....
And I might get convinced once art museums or exhibitions open "contemporary departments for miniature painting" and essays appear about that in schoolbooks and academia.
But not before