But yeah, I agree that it definitely should have been new blood. Kamiko, Sakurako, Mizuho... that sounds great. Thanks to Juan.
They do have something about them. Sakurako is really adorable but usually in the back of Kobushi, even more than Taguchi and sometimes Rio, but she's actually a decent singer and not unpopular. Mizuho has an interesting voice, it's quite deep, and while I don't know if her singing is that good I think it adds something much needed to Tsubaki - unfortunately they even shoved her out of the focus to promote Kiki along with the other two newbies. Kamiko is just amazing on her own, one of the best additions to H!P in the last few years
And I noticed that you took Akane off that list ( ), I understand it though haha. I love her, but performance-wise she's not that great (and she isn't new either).
With Nksk it's pretty obvious that the group won't have more than one release, though.