Appointment vs sub grade, which one shows a higher cep?

Assuming that both of us are from the same batch,

Me: Appointed HOD, geo 5
Colleague: appointed SH, SEO 1

I am very disappointed that my colleague who came in at the same time got promoted to seo1 before me. I am certain that she is not a kid career switch. She is covering the hod, but yet to be appointed while I have already been a head for two years.