Thank you all for your feedback, I no longer need an answer to the question and would appreciate if everyone else kept their opinions on vow renewals to themselves.
We started kind backwards. We aren't having children at our wedding/renewal outside of those in the ceremony, because of numbers, so we put any children we wanted there in the party. Our friends two boys (1.5 and 5) will be ring bearers and our daughter (1.5) and a friends daughter (5) will be flower girls, and his niece (12) will be a junior bridesmaid. We have a best man and matron of honor, but we don't know how many to have after that. I feel weird having more flower girls and ring bearers than actual attendants. He is fine having none other than the honor attendants so his friends don't think some are more or less important than others. Customarily wed have four males take part in the ceremony, but we are trying to keep it small. I'd like it to not be apparent that we just allowed some kids but not any others and having more kids than adult attendants seems obvious. We both have large families with lots of kids and a budget too tight to allow children. Suggestions on how many to have?