Should Bridesmaids Have the Same Hairstyle?

Hey Ladies. So my FH has a huge family and a lot of friends, therefore my Bridal Party will consist of 11 Bridesmaids and 11 Groomsmen. I know its a lot, but 11 is a significant number in our relationship. Any-who, being that I have so many bridesmaids, I had the idea of them all wearing dresses that are of course the same color and material, but also have them pick what they are comfortable in, what looks and feels good to them, and whatever is their style. With that being said, being that the dresses will be different, should the hair be uniform? Whats your opinion?