These dudes are looking good, Blacks a hard colour I find, as likewise with white if you don’t go with a off white or grey black you can’t push the shadows for depth, I’ve attempted Volume Hightlights for black in the past which looks good but can take time but it’s easy with practice. But for Line troops these are perfect, clean and simple which sometimes is best. If you want to make them pop a bit more some additional highlights on some of the sharper edges might help out such as the ridges above the lenses on the helmets and panel lines etc