I think that from this, we can safely say that Haibel is el Seieto Espada, #7.
Think about it. Noitora cannot stand a woman in a higher rank than him. The only woman on the Espada is Haibel herself. So, if we take a look at the current Espada ranks, (including the deceased) we get this.
10 - Yami
9 - Arroniro (aka Kaien)
8 - Salazayel
7 - ?
6 - Grimmjow
So if Noitora hates women in higher rank (the sexist prick....) then he would have taken care of Haibel if she were in positions 3, 2, or 1. Therefore, those positions belong to Stark, the black dude with the skull earings and skull spikes, and the old man.
Personally, I think the old geezer is #1, Stark is #2, and the black dude is #3. Kubo likes his older characters to pack a punch, which is my reasoning for #1. No particular reasoning for #2 &3, I'm just going on a hunch.
Anyway, didn't Kubo show a few chapters ago how the Hollows evolve? He said that D-roy would never become a Vastrolorde, from his broken mask. Ergo, broken mask = broken powers.
How could Dondochakra's and Peshe's masks be broken? We would have seen it. We've seen them from almost ever angle imaginable since the team broke into Las Noches. Especially since they started fighting with Salazayel (when will it end?!).
'Til next time, cheerio.
Nobody is perfect. I am a nobody.
Therfore, I am perfect.