inHistiming,
I'm thinking that you've had some very tough health and medical issues this past year and have also had a new baby and possibly even a move, if I'm remembering correctly? Certainly, all of these things will affect how much progress you've been able to make and also how much of a rhythm you've been able to get into with HOD.

I also agree that with a larger family it is wise to pursue combining those who can combine successfully.
So, with those thoughts in mind, I would take a good look to see if your almost 8 year old has the skills to do what is written on the left side of the Preparing Hearts guide, as well as much of the right side. If he fits well there on the placement chart then that is a very viable option. However, if your just turned 8 year old ends up doing little more than listening in to the readings within Preparing Hearts, then this is only a one-year temporary fix because at some point the skills that little honey is missing will need to be addressed, making him unable to move into CTC the following year without you doing all of the reading aloud.
If you are not liking your older child being off doing his own guide, then he can certainly be with the rest of the family when doing his guide simply by moving him into your mix. I know my 6th grade son who is doing Resurrection to Reformation is among us all day, so there is no feeling that he is off by himself. He shares things that he's reading with us and talks with his brothers as he works. We see him all throughout our day. There are many ways to get your son more involved with the rest of the family if desired, as it is up to you to decide where he does his schooling each day and what he is sharing with others and how. Often the family feeling is as much about where the child is doing his schoolwork within the house, as it is about what the child is actually doing.
My oldest son does choose to do his work upstairs much of the time, but since he is in high school, we feel this is alright as more quiet is needed for his studies. He does come down in between each subject and is among us then.

I also check on him off and on throughout the mornings to see if he needs me.
We do all eat lunch together, and each of my boys has a scheduled 30 min. playtime with his younger brother during the morning too.

Right after lunch, all of my boys clean up together and then head out for a 60 min. recess together too. Around lunch we talk about their subjects and often I do a read-aloud or anything else I have scheduled for the year for all of us to share together from someone else's guide.
One other thought I'd wondered about is whether your older two could possibly do CTC together instead of being in two separate programs? This would be something to weigh that may allow you to work in a more focused way with your younger student in Beyond. Or, if you could do Beyond at half-speed that would work too. Sometimes it does take time to work out a schedule that is viable.

Depending on how far into Preparing Hearts you are, and on whether your daughter in Preparing has done Bigger, you could also consider combining your almost 8 year old with his older sister within Bigger Hearts instead. That would allow you to meet both of their needs while still having them together.

I think that you need a plan to combine some kiddos if possible for the longer term, and it is just a matter of figuring out who combines best and within which guide.
One last thing to weigh is how much time your language arts and math are taking for each child each day. I'm not sure if you use our recommendations in those areas, but it can be shocking how much time language arts and math alone can eat up in a schedule daily, especially if you have quite a few kiddos. So that is something to calculate and get into balance too. You can use your own options if desired in these areas, but just make sure that they are in balance time-wise with what we're scheduling in our guides so that the language arts and math are not making your day go on too long or taking too much precious mom time.
If you have other thoughts, post back and we''ll talk through options until we find what is best for your unique family situation.
Blessings,
Carrie