Lynn,
The ladies have given you such wonderful suggestions that are worth a try. This board is such a blessing at it is full of ladies blessed with wisdom and empathy!
I have other suggestions that I could offer but I hesitate to have you do too much to the reading, in the fear that it may take the joy out of the readings for your sweet little guy.

One thing I do want to share is that in CTC since we are having kiddos take over their history readings on their own for the first time, we are not expecting excellent comprehension. The reason for this is that doing the reading on one's own IS actually the skill being introduced. In RTR we will practice this skill and by the following guide, we will be expecting very good comprehension on the readings.
At HOD, skills are always introduced in stages in our guides, and its hard not to expect mastery the first time a skill appears. But the skill of reading to oneself and comprehending it is simply being introduced in this guide. That is why the follow-up assignments for the reading are not as involved in the comprehension area as they were requirement-wise in Preparing Hearts. We know this is a first time out for independent reading of the history texts. This in itself is no easy feat! Simply getting through the text and having some idea of what it is about is a good first step.
I liken this to the transition from an oral narration to a written narration. Once kiddos have been orally narrating very well, they are ready to move on to written narrations. However, when kiddos first begin written narrations, it is normal to expect a very short written narration that is nowhere near what the child would have given you in oral form. This is because it is a new skill, requiring the coming together of the oral and written word (including punctuation, spelling, capitalization, grammar, and simply getting words out of the mind onto the paper in a cohesive form).
The same is true for the history readings. Once kiddos take over this large task, it takes a bit to read and comprehend, even if the story is a familiar one. Plus, the vocabulary used in the living books in CTC is not easy either. So, the kiddos are actually decoding while reading, trying to figure out what the text is saying, trying to assimilate the information into what they already know, and then trying to do a follow-up assignment on what they read. You'll find that the activities in CTC actually layer over one another to aid in better comprehension, making sure the history text isn't the only time kiddos have heard or seen the information. So, kiddos will read it in a different format in their Bible readings, get a different slant on the place in the Geography of the Bible Lands, hear more about the topic in Diana Waring, draw or sketch about it in the Draw and Write, hear a book from the time period in the Storytime and so on. All work together to aid in comprehension.
So, I would honestly let Noah wade through the history reading making his own connections. I would be careful not to "do" too much to the text or make him think he's not doing it right. Otherwise, he will begin trying to read for the one right answer, rather than trying to make his own sense of it, and the working through the text to make his own sense of it is the valuable part.

If he can do the activities in the guide and get through the text, then he is doing what we would expect of him in CTC. He is learning to take over the history readings on his own. This is the introductory stage of this skill. Comprehension will come in the coming years as the skill is practiced. Think of it as a journey!
Blessings,
Carrie