Well, I'll toss in my two cents. When it comes to painting there's what is possible and then there's what is necessary. It's possible to do two reasonably identical eyes and include details like iris, pupil, and catch light. But for a 54mm or smaller scale is it necessary? In person, unless you really get up close and personal with the figure, you aren't going to notice all of the eye details. You get an impression of the eyes but you won't notice if they're perfect or not. If they're too far off then yeah, you'll notice. But close can often be good enough. The online pictures tend to show these figures larger than life so you see more detail. For the Crystal Brush where you depend on the online voting for half your score, it's worthwhile to look at the size of the pictures and how your figure would appear at that resolution. Check out the gallery and see how your entry will look at the same scale/resolution.
http://crystalbrush.coolminiornot.com/cbgallery
And of course the sculpt plays a large role in how easy or difficult the eyes are to paint. Sounds like the sculpt here wasn't doing you any favors.
On a side note, Blood, have you painted any eyebrows on this guy? I know he's got light hair so maybe it's just not showing up to my eyes. Either way, I'd start with the darker hair color and then sketch in the lighter one so the dark still shows through, giving the impression of texture.
Here are a couple eyes I've done recently. For Gokan (54mm) I didn't worry as much about details, but I did want to add a catch light. I think the size and shape of the irises is pretty consistent, but with the shadows it's hard to tell. I think it looks good enough so I'm happy.
For the Dragoon (54mm) I tried to get both a blue iris, black pupil, and white catch light. The catch light worked better on his right eye, I was a little unsure how to deal with the light in his left eye considering the helmet would block it. I went for a subtle dot but it doesn't really show up. Meanwhile the pupil ended up being much crisper in his left eye than his right. But, in both the full body pictures and in person you aren't going to notice any of that. That's part of the reason I didn't bother with the detail as much on Gokan. However the catch light can still show up in the full figure photos. So I think that is worth trying at this scale.
And going to a larger scale, 90mm, the eyes are much more important (well, much easier to see). With much more room to work I put a lot more detail in here, however they still aren't perfect. The pupil size is different in each eye. I've tried to fix it and may go back in again to see if I can tweak it. But, in the end, sometimes you just have to live with what you get. Will the difference be noticeable in person or in the online full figure photos (not just the close ups)? Probably not, so does it matter?
Blood, if it looks good to you and will look good in the Crystal Brush size photos, then it's good! If you did want to tweak, I'd suggest trying to add a catch light dot. Other people will use a gloss coat on the eyes to get the effect. And, as I mentioned above, eyebrows!
Oh! And another trick is to have the eyes looking off to one side. When they're dead center the face can look a little more static and size/spacing can be less forgiving. In both the Dragoon and Roman the eyes are looking slightly to the figure's right. If you were to redo them here (which I'm not saying you should do) then I'd have them looking off to his left. His head is titled that way so it'd be nice for the eyes to match the pose. Straight ahead is fine but off to the right would look wrong (why turn your head left and then look right?).