Please bear in mind that I don't have much experience in this kind of thing, BUT, that said, I think the problem with the spearmen is that the colors you're using in them are too close both in terms of contrast and saturation as the castle behind them. Thus (i suspect...) they seem recessed and therefore huge. Also it's easy to read them as statues because gray = rock, usually.
So maybe if you separated the parts of the armor more, created areas (clusters, if you will) of a higher range of value and maybe also some areas of color (capes? scarves? standards? a colorful shield?), then I think they would come forward and stand out a bit more.
As for the clouds... They look very busy at the moment.
But especially for this last piece, you're going for a very detailed style, so I don't really know exactly what to tell you... Fewer clouds, maybe? More detail at the top of the clouds, less detail at the bottom? Lower contrast for those at the back?
Those are just guesses, though.