what are the real sorority rankings here?

With only 6 fraterinites (soon to be 7 when the Pi Kapps get their charter) on campus, the "tier list" isnt really applicable, most fraternities are carbon copy men that constantly recruit carbon copy rushees to get along with their chapter (minus Alpha Gamma Rho, Theta Chi, and Pi Kappa Phi.)
Also, with only 7 sororities (soon to lose Delta Sigma Theta and gain Alpha Gamma Delta) the smaller school also dosen't allow a true "tier list" to be established. Most girls with a "well-rounded" life (attractiveness, social, involvement) are usually hand-picked by KD, ZTA, and ADPi, but Gamma Phi Beta is definitely on the recent rise since coming (back?) onto campus.

top tier : alpha delta pi, kappa delta
middle: alpha chi omega, zeta tau alpha, gamma phi beta
botton: alpha omicron pi, tri delta

Top: ADPi, KD
Middle: ZTA, Tri Delt, AXO
Bottom: AOPi, GPB