Using FP+ for large group- adults and small children

[twd08]

My family is visiting WDW March 2015. This will be our first trip using FP+. Our group will include my parents, early 60s, my sister and our spouses, 30s, and our children, 10, 4 and 2. It will be the 4YO first trip. I am trying to optimize our time by getting our group to RD. I am also hoping to utilize FP + for half the group on an adult ride and use rider swap/switching off, while also using FP+ for a close by children's ride so the little ones won't spend too much time waiting. I am aware that children must be present to get the rider swap ticket. Does this sound far fetched? Anyone use this method with success before? I am thinking mainly of MK in this scenario. For example, FP+ 7DMT for half group, Dumbo for my sister and I, and the 2 and 4 year old. Go to 7DMT with group, get swap off pass, take kids to ride while half adults ride, return and ride ourselves with pass. Is that too much? Crazy?