@Matt as for eyes, I think those guys look fine as is! Grizzled vets with eyes shadowed by their helmets and all that. (I almost never paint eyes myself, or at most just fill in the whole eye with white. If blank white eyes are good enough for old Jes Goodwin concept art, they're good enough for me!

)
Incerdentally, and sort of tying in with some chat we had about painting in the "too much of a good thing" thread, the Black Magic Craft guy (a pro-click channel for neat videos about terrain projects!) recently posted a video about his own philosophy towards painting:
https://www.youtube.com/watch?v=ee_xAxjbDfA, where he begins by talking about how the profusion of high-level pro painter channels on YouTube has probably warped a lot of people's ideas about painting goals.
And it really speaks to me personally (and describes my own painting technique pretty well to boot*). You can get some awfully good results if you shoot for "quick and good enough" for whatever your own personal values of "quick" and "good enough" may be, and figure out techniques that support that balance - that's a lot of how I've been able to bash out, er, 112 (I had to go back and count) miniatures for Darkest Dungeon in just over a month to a level that I'm very pleased with.
*Although I do drybrush instead of airbrush for preshading, almost never use actual metallics any more, don't fuss with oil washes (cleanup being a relative pain) and am not much of a fan of gore on minis. Everything else, though, is Pretty Much How I Do It.