Stawna,
The ladies are doing such a good job of helping you talk through possible helps.

My first week is usually pretty crazy too, so don't be discouraged. Things will settle down!
I just wanted to let you know that we typically do advise for families with multiple HOD guides going to do only one Storytime. So, it is a good move to combine your CTC child with your Bigger child for Storytime. Since you're also doing LHFHG though, we do advise that you keep the LHFHG storytime just for your little one as it is so short and includes so many needed skills!
I would encourage you to keep your CTC child doing the BIble in CTC though. It is meant to be an independent skill and is a necessary part of CTC. Plus, the Bible within Bigger is targeted for the youngers and meant to focus on Godly character for that particular age.
As far as moving ahead to full-speed goes, I would only plan to work toward getting your oldest child up to full speed first. Keep your Bigger child and your LHFHG child at half-speed until the CTC is doing well at full-speed. Next, move your Bigger child up to full-speed, keeping your littlest one at half-speed until you successfully have your Bigger child going at full-speed. If your Bigger child can't make it up to full-speed for months up to even one full school-year that is alright. Work done well is the goal, rather than cramming it in.

Bigger is our biggest teaching guide time-wise, because it is all "you" with little independence. However that training/teaching is so important and will hold your child in good stead as he/she heads into Preparing.
Last, you'll move your LHFHG child up to full-speed. If your Bigger child takes his/her time gaining to full-speed, it is possible that your little one could remain at half-speed all year. That is alright. Just remember that you need to get your older two going well and able to do what is being asked of them in the guide first before ever moving your little one up to full-speed. This is key, and the process cannot be rushed!
Prioritize from the top down for now, keeping in mind that your 7 year old is on the very youngest age range of Bigger, giving that child plenty of time to move through Bigger at a less rigorous pace. Your 5 year old is also on the youngest age range of LHFHG, giving that child plenty of time to move through LHFHG! So, focus on your oldest child first. Training is the key to success!
Blessings,
Carrie