Frequently when a merge is proposed, it will impact other relationships. When a merge is proposed, it is good practice to check the spouse profiles, as well as parents and children to see if there are other duplicates. If merges are all proposed at the same time, it will speed up the process of getting them all merged, especially if you have to wait the default 30 days for each merge. The parents profiles should always be merged first so they don't have to be chosen on the children profiles.