Which parks and when depends on how long you are staying which you didn’t mention. I think you should plan that you all go to same park each day, but it sounds like a group of 8 and you may want to divide at times. Maybe book a few TS meals in parks to reconnect if you did divide up for part of the day, for example. It’s likely, for example, that PawPaw, mom, and 3 yo take things slower at times, for example, as the youngest and oldest are going to be more limited on ride choices. When I travel with family, there’s always some together time and some separate time in the parks. We’d drive each other crazy if we spent the whole time together each day. By dividing part of the time in the parks, we get the best of both worlds.
I find the goal of everyone leaving at the same time in the morning works well because it means there is breakfast eating and getting ready time that you are all working through at the same time.