5 sisters, 2 bridesmaids

Help! I need advice! I come a large family I have 5 sisters and I planned to only have 2 of them be bridesmaids in my wedding. My FH has one sister and not very many friends (I feel like it's real life Best Man with Paul Rudd and Jason Segel) anyway I have always known that my older sister closest to.me in age would be my MOH. At the beginning of planning we discussed only having my sister as the MOH and her husband (my BIL) as the best man as me and my fiance met through them.



Somewhere down the line my FH asked his other BIL to be a groomsman so I had to come up with another bridesmaid. I planned to ask my younger sister as we are the next closest relationship wise.
My only issue is I still have 3 other sisters who I won't be including and i feel bad about it! To be fair of those 3 who are all married I was only asked to be in one of their weddings.
I have considered including them in my family processional, giving them a corsage, and asking them to be either greeters/ushers, and also asking them to wear my wedding colors (I am not having specific bridesmaid dresses) is this acceptable?
I know it's my day, but I do want them to feel included because I do love them! I just dont want to hurt their feelings or look like I am doing anything out of obligation.
I am welcoming all opinions because I am so torn!