@sssr That was the impression that i got as well, though without seeing the raw it's also possible that the seemingly inverted labeling is a joke on the asterisked note that there are many different standards for slime ranking. Also, it is amusing that the lowest ranked slime has Yoshida's hat and glasses. 😄
Edit: Also, though there is little medieval history content in this chapter, I think it qualifies as a fanservice chapter, since the most realistically proportioned we've seen Yoshida is when she's being assaulted by the slime.