Wow! Thank you for all of these amazing replies! I have been wanting to get back here so I could finally reply myself. I am sorry I haven't been able to until now! I did read everyone's responses right away though, and have been thinking and praying about this.
As for the placement chart, at first it seemed like my 6yo fit squarely into... BOTH Little Hearts and Beyond - haha! Upon further examination though, I really think he would probably fit more squarely into Beyond. Since he is a young 6 still, I am sure that we would do fine with LHFHG w/the 1st grade options IF I started now. I talked to DH though and he would prefer if I waited until the Fall. Even though I would really like to switch to HOD now, we really do have more than enough to finish out the school year. It is just that I am really unhappy with our school year. The planning and pulling together is overwhelming and discouraging. By the time I get to teach it, I'm not too excited about it and I think that rubs off on the kids. I knew I should have chosen Little Hearts for this year! Beyond is probably going to be the best way to go in the Fall, and I am REALLY sad that my older one will miss out on Little Hearts. For example, we have Devotions for the Children's Hour which we randomly read from for the 1st time the other day and we LOVED it! Sure I could continue to read through it the rest of the year, but I am sure that HOD has it planned out and tied into the lessons way better than I ever could! Plus the rest of LHFHG just looks so fun. He could really use the fine motor skill activities in LHFHG. Also, I would much prefer a creation to present day overview for 1st grade and then Early American History for 2nd grade. Maybe that won't work for us though, since he is on the older end for his grade. I really am going to need to go with Beyond in the Fall since he will be turning 7 (and places in Beyond even now). I would not hesitate to use LHFHG with a 6yo 1st grader, but I probably shouldn't with a 7yo 1st grader. Maybe I could find LHFHG used and start now, planning to sell some of the curriculum that we currently own.
Oh and a little more about my kiddos... they are all boys!

Initially I was thinking that I could easily combine the older 2 because my oldest, while he is very smart and able, and probably right on or above for his age, he is not crazy about "doing school". He just wants to play all day! My 4yo however, WANTS and LOVES to "do school". He is always begging for it. He is not ready for longer readings or books without pictures though (well not now, but maybe in the Fall!).
Thank you momof3kids for sharing that idea about starting LHTH now. That does sound like a good idea!
Oh, I don't know. You all have been so helpful! Definitely let me know if you have anymore advice!! Hope you are all still checking this thread. I will reply quicker next time.