Yeah I ranked Nancy last not because I liked her the least, but rather because she's currently suffering the same problem I have with Stabby Mike (which I've elaborated on in this thread a while back): In that unless something changes in the future, she's pretty much "done" from a character development perspective, and the only thing to look forward to with her are the sex hijinks she and Orion might partake in within and outside Eternum and her bonding with the girls.
I mean, what else is there to do with her? Have her have an arc where she goes through the role of a ruler and realizes she's slowly going mad with power? Have her go the OIAL Rebecca route where she realizes her relationship with Orion is wrong and she distances herself from him, only to bounce back because our horndog of an MC wouldn't let her?
Compare that to the rest of the girls where not only are their growth arcs not done yet, but their stories are a lot more interesting to see develop. So yeah, I suppose the ranking is less of who I think is best girl, and more of which girl's story and growth I find interesting at the moment.