Is your first grader your youngest child? If not then ignore everything I'm about to say
If so then you would need to work based on amount of teaching time compared to amount of independent work. What *I* would do is to start with teaching the WG child anything that you have to teach them. Then you would be done with that child until you checked back in at the end of the day (I'd probably suggest checking in after your younger ones are done for the day and then again after WG is done). I would then teach my CTC child their T and S boxes and be done except for checking in, and then JUST do the S boxes with Preparing child and send that one off to do the rest of the S boxes and the I boxes. I'd use that time where everyone else is working independently to teach the 1st grader. When that child is done the Preparing child would likely be ready for you to do the T boxes with her (I work up to where they are reading their own history by the end of preparing actually. I start with them reading once or twice a week, depending on their age and reading/comprehension). At that point, it's likely that everyone will need a break, and possible that the CTC child will be done and ready for you to check in with them. So I'd use that time to break for lunch. After lunch I would finish up anything left over from the younger guides and check with the older ones in the high school guides.
It seems like you'd be bouncing back and forth, but really you would have 5 blocks of time that would be done at least by lunch time if not before (depending on when you start school).... teaching WG, teaching CTC, semi ind boxes with Preparing, 1st grader, teaching Preparing.
After you really get rolling it almost flows on it's own once they get in the more independent guides.... starting with Preparing!