I think too much over analyzing happening here.
Women are allowed initiation into the Khalsa. Khalsa is a saint soldier who is PURE, and can through this purity MERGE with the PURE ONE-->GOD. Lets all try to become Pure first in all actions and thoughts.
Guru Gobind Singh: Father of the Khalsa...is the NIRGUN ROOP OF AKAL
Mata Sahib Kaur - MOTHER of the Khalsa --is the SARGUN ROOP OF AKAL or AKAL SHAKTI. Manifestation of the NIRGUN ROOP.
There is only ONE GOD ==NIRGUN ROOP OR SARGUN ROOP. Lets try to get out of DUALITY, and focus on the "oneness".
The khalsa is equal part female and male. Khalsa is for all genders. This tradition of women not being in the Panj Pyare. Perhaps because the original Panj Pyare were all men. It would have been nice if a women had volunteered her HEAD when the KHALSA was originally created in 1699, as that did not happen. As a women I am very strong and confident in myself, and believe my father, Guru Ji, and don't need to question gender equality. We know our religion is all about Gender Equality, so why keep bringing something up that has no relevance.
If you feel good if women are part of the 5, than go for it --take amrit there, However, there is nothing wrong with tradition, and the 5 being men. Lets become Pure, and uphold the values of the Khalsa.
This questioning is a slippery slope, as so many things don't make sense. However, as you start praying the answers come to you.
Crsytal - Just pray to Guru Ji, and ask him this question. He will answer...