You've already gotten lots of wise advice here! It gives me reassurance to think that Carrie herself has 4 very busy boys, at all different levels, so she is planning for that as she writes. I find HOD's curriculums take into account that time must be spent with the young ones if the day is going to function at all. They just beg for attention, and demand it in any way they can! (at least at my house)

Each HOD program we do gets more independent. Preparing... is heading that direction as well. I think that it is wise to start with our teaching time being spent with the youngers, and then move them more to being independent each year.
Also, when they are ready for it, if they show a desire (and aptitude) to take more of the lead, a natural reward is to let them try. For example, my ds doing Bigger... is now at the point where he uses the guide, and checks off boxes as they are completed. As I finish doing what needs to be done with our baby, and I finish something teacher directed with my other ds doing LHFHG, I ask oldest ds doing Bigger... what he's ready to do with me or what he needs me for. I go back and forth between dear baby, LHFHG son, and checking in with Bigger... son like this until schoolis done. This has worked out great, and as he's gained confidence and ability in doing this, I have let him choose the order he wishes to do Bigger... in too. He loves this role he's growing into, and I am thankful for it. I think if our dc show they are ready for more responsibility, as long as it doesn't hinder the learning, why not let them try to take that on? I know I'll be thankful when I begin doing 3 programs.
In Christ,
Julie