I understand the impulse to focus more on one style: it creates visual cohesion in your shop, but in your case I honestly think that they all work very well together. However, that isn't very helpful, I know!
Maybe this will be more helpful: I've noticed that more figurative (and less abstract) work tends to do well on Etsy. If you are game, it might be worthwhile to lean toward the more figurative black ink drawings for a while and see what sort of response you get.
In my experience, responding to interest and demand can strengthen your work. My figurines have definitely evolved in response to demand. I sell more figurines that resemble specific breeds and species of animals than figurines that are purely imaginative, although over time, as my work gets out there more, this is becoming less significant.
Your shop looks fantastic, by the way! All my best to you!