All of them stunning! It is so neat to see you do a chestnut friesian. It is something I don't really understand, the strict elimination of a color like that which has no detrimental effect on anything. I suppose it's just the "fashion" part of breed selection, but I think they are really elegant looking just like the black! In any case, your depiction is very handsome.
I like the little Sandalwood! That coat is incredible. To me the only coat pattern that seems harder than a dapple gray would be a fleabitten gray. You really nailed the technique for this scale. It's funny, I rode a little gray pony in Indonesia. I doubt these were very good examples of any specific breed, but they did resemble what you describe. (You have to ignore my terrible form there, haha, the tack and the horse were all too small for me, the poor thing!! It was sort of a surprise ride that we got hustled into. They got us again later when I was even less prepared, in my flip flops.) This was the basic body type of every horse we saw, and there were more of them than I expected in Jakarta, all work horses.
Brilliant work on the chestnut dapples. They definitely did not ruin the coat color at all but really made it pop!