One thing Carrie said in a recent thread is that 3 of her boys were different ages going through the guides (younger age, middle age and higher end of the recommended age range per guide). She said something like, each son got some thing different out of each guide but each benefited appropriately at that age.
That really resonated with me because I totally see that with my second time through LHTH with my two girls. My ds (a wiggly boy who would rather build forts all day) was 5 when we did LHTH. We used it for kindergarten with no additional material. The letter sounds and recognition were a bit too easy for him, but good reinforcement and our first homeschooling experience. I needed to ease in too.

He loved the Bible Stories and activities and other crafts, rhymes and drama. We spent double the recommended time it is supposed to take because he wanted to look up the Bible story in the Scripture and read and read before and after the story topic of the lesson. He wanted to act and re-act out the events over and over. This is mostly just his personality.
We moved right into LHFHG the next year and then Beyond the following year (current). I would say it has been a good fit placement wise each year with perhaps a bit of a challenge in the basics. He is not a strong reader or writer, yet.

We are still in phonics and he can hardly do the copywork required in Beyond. I am seriously considering going half speed with Bigger next year with him because it is supposedly more writing intensive (plus I'll have a new baby). If I use bigger for 2 grades, he will end up at the upper age range of the next guide, and hopefully mature in reading and writing along the way.
Someone said here a while back she feels her children do best at the upper end of the age ranges. They get the most out of it. I can see this based on what my 6 year old ds got out of LHTH and LHFHG, especially the history, which I think is an important element of HOD, and he has been middle age range.
My girls are 4 and in LHTH now. They are not doing nearly as well as ds did at age 5. They can barely remember the Bible Story facts and don't want any embellishments, are not nearly as attentive. Plus, there are two of them at a time which adds a dimension. They are loving the letter activities and I find my girls are a perfect age and readiness for learning such. Overall I feel LHTH is a good fit, even though it is more surface than what my son got out of it. They need that introduction to the Bible stories even if they cannot remember too many details. My son reveled in the details.
I know what's coming in the next guide, LHFHG. Especially the history. I don't think my girls will be able to listen and get very much out of it. I know they will do good with the fine motor skills workbooks and probably with the K handwriting as well, but with having other children (older, younger and newborn). I'm planning on trying to keep it simple. I don't see combining in my future so going slow is another option to help them grow up into the older age range. I think they will get more out of the readings and Bible verses especially.
I am actually considering waiting a year and starting them at 6 in LHFHG instead of the half speed idea, but going ahead with The Reading Lesson and maybe the workbooks (not math). I don't think there is a hurry to get the history into them at such a young age. If they can start LHFHG already reading at 6, that would be a bonus.
My first idea was going half speed with my ds in BIgger and half speed with my girls in LHFHG because I thought it would be a big step for all of them, and me (with a newborn). But the more I look at it (like History for little pilgrims, which is rich and enjoyable) I just don't think my twins are ready for it. I would be better off taking that time on phonics and fine motor skills and starting them at 6, while putting them in the middle age range. I will still have them listen in to ds's storytime to practice listening skills, or perhaps read a book just with them.
Hope this helps a bit,
Bless you on your homeschool journey.