Cool, minimalistic and very finely done conversions!
For variety, I'd focus on a face or two. Hard work, but you (or rather, me) usually recognize the face, and when the same two faces keep alternating on the front rank, the effect of conversion work elswhere isn't that obvious. These models have quite broad faces/foreheads, so maybe a careful thinning and then some GS work on the nose would change the face enough. Perhaps just a repositioning of the feathers would do the trick?
I find the Flammberge pose is nice. If only the sword is a problem, maybe change the sword blade?
None of this is meant as criticism. I think your GS skills are excellent, and you could achieve even more variety.
-Z