Ideas for female roles other than bridesmaids.

I have 3 sisters but I'm closer to my friends than them. I still feel like I have to have my sister's as bridesmaids. I have 3 friends that must bebridesmaids / maid of honor. However I have 5 more I really want to be more than just a guest. He has 5 groomsmen and a best man. I thought of doing 2 women with 1 man for half the guys so 9 women but what roles could the other 2 women play? Someone mentioned having one get ordained and handle the ceremony as well as any announcements at reception and play the role of master of ceremonies. I know usher is an option but the seating isn't formal so I don't think we need ushers it would seem like a useless title. I would rather not include them if the inclusion seems rude. I feel like it's easier to explain I have 3 sisters than to have them be offended I asked them to participate in a way they don't like. Example my baby sister is ordained I originally asked her to marry us and she was upset that she wouldn't be a bridesmaid. Had I just said we are keeping a small ceremony and had 3 bridesmaids that weren't my sister's I think she would've been fine. But 6 & none were her was insulting... Apparently.