Well this is what we know: Yammy #10 Arroniro #9 Zaero-Polo #8 Grimmjow #6 Ulquiorra #4 So that leaves only 5 members left... -Stark -Black guy with the mohawk -Halibel -Old man -Noitorra just don't know who could be number 1... Here's a pic of everyone Starting from the left: Ulquiorra, Stark, Noitorra, Halibel, Arroniro, Yammy, Old Man, Zaero, Mohawk guy and Grimmjow
I'm saying Halibel is #1 and Noitora is #2. followed by Old Man #3, then Stark, then Black dude w/ Mohawk order of rank, those are just my thoughts.
Noitorra is #1 I think, because he said he was the strongest Arrancar. And Halibel came to stop Sado when he wanted to attack Noitorra. When that happened Noitorra got angry at Halibel and he got scared like hell. So I don't think Halibel is stronger than Noitorra, seriously.