Doing multiple HOD guides is not the same as doing multiple guides of other curriculums. I would not be able to do 3 guides of another curriculum as easily and happily as I am able to do 3 guides with HOD.

I'll try to explain as best I can. As dc grow and mature, they move through the HOD guides sequentially, and this incrementally moves them along in both skills and in independence, which is necessary as dc age.

The amount of time dc spend doing school, and the amount of time a parent is teaching, begin small and steadily increase from 30 minutes in Little Hands to Heaven, to about 3 hours in Bigger Hearts for His Glory. These are crucial teaching years, and worth every bit of time we as parents put into them. We reap the rewards of solid, steady, step-by-step teaching within these initial years for every year to come after them.
Once dc complete Bigger Hearts for His Glory, they are ready for Preparing Hearts for His Glory, which takes around 3 1/2 to 4 hours. However, this is the point a parent's teaching time begins decreasing. Charlotte Mason clearly said that it is crucial for dc to take over their own reading in school by the age of 9, or shortly after if a student is not able to at 9 yo. PHFHG begins to have dc do this with the independent science box. The years to follow steadily have dc taking over more of their reading and learning. This is an important part of education! It is what encourages them to grow and mature, and it is what frees up time for us to have time to teach a rotation of specific more mature skills to our dc - rather than just read endlessly to them.

This also frees up time for us to teach our younger dc, and they need us. This makes teaching with multiple HOD programs an incredible blessing. It makes the days flow very smoothly, and it recognizes that different aged dc have different needs.
Here is our school schedule this year, and what you see on paper is what happens every day.

It's not one of those hypothetical schedules we're "shooting for". It's one of those schedules that works consistently each and every day, and it has to, because I am a very busy mom who loves to homeschool but who has other responsibilities to my Lord, my dh, myself, my dc, my parents, etc. that are important too. I don't think I'm alone in these responsibilities - I bet you have them too!

HOD makes me balanced not only in our schooling, but in my life. I can homeschool this way and find great joy in it! I am not stressed, I am not unhappy, I am not stretched too far, and my dc are thriving academically and spiritually! I want this for you too!
Please keep asking questions here until you have a plan figured out, but don't worry about doing multiple guides. HOD makes that very manageable, extremely open and go. I never open any of the 3 guides I am teaching for the day until I am going to begin teaching. You can't get more open and go than that. HTH!
In Christ,
Julie