As our friend from Ireland said, "sometimes"(like, about 99% of the time...),many Americans tend to act on the idea that if some is good, more is bound to be better...actually--NOT USUALLY, in my observation. An animal with a complete body covering of hair has it for a reason, you know; depriving them almost COMPLETELY of that, over all, or a major portion of, their body, is not a very good idea, nor a very kind thing to do, I strongly feel. Like Sue C., I see absolutely NO point in "skinning" our horses( and for sure, no benefit to the horse!!)Certainly, one 'should' presume that anyone who does so, would then take all steps to compensate for the near-total loss of the natural protection(by blanketing, protection from both heat(direct sun) AND cold--but living the time I have, and seeing the human behavior I have seen---well, I wouldn't bet on that being a certainty.
I have never, and would never, clip the major portion of the body with anything that clips closer than a #10 blade. As I wouldn't razor, I have used a 30, 40, and a 50 on various places on the face, tapering each area into the other. The photos of Mingus are absolute proof that a miniature can look absolutely smashing in natural coat(and he is now a gelding, so it's not the hormones!)
Based on the look of the hair coat of the horse about whom the original question was asked, I would continue with the # 10 blade-his color looks great, and he looks slick and healthy! And as for that super-close clipping making a horse look 'tighter'(??), or enabling judges to 'see'musculature better--all I will say is--oh, please.....!
It is true that at the time of the two miniature "national" shows, most if not all people wait until they arrive there to clip their (halter)horses. Horses have already started significant production of their winter hair coats by that time of year, and are going to try to replace the clipped-off hair VERY quickly by then. A very clean and dry horse, good sharp blades, and a knowledgable clipper are very important-but that combo can produce a gorgeous horse, the day before the class--with a # 10 blade--I have seen it happen, many a time!
(And yes, body clipping, in many cases, is followed by a pretty icky looking grow-out of the hair coat!) I haven't touched any of my horses with a body-clipping this year--and they look SOOO nice! Not saying I will never body clip again--but if/when I do, it'll be with nothing that cuts shorter than a #10... .