I am someone who came to programming via "teach yourself vb6 in 24 hours" type books.
Through a desire to understand what goes on under the surface I came across Charles Petzold's
book "Code". I got about half way into this but at that stage I started to woder how well I was understanding things as there was no way of testing myself.
Then I came across this book and it was like my dreams come true.
I'm not finding it very easy ( I'm only now on chapter 5 and didn't feel able to face this chapter until I had revisited the previous 4 chapters several times).
Each time I revisited those chapters I learned something that i had missed the previous time.
Some things surprised me. Like how the ALU chip is so easy to make, easier than some of the Muxs and DMuxs.
Maybe because it was manageable I made eg the Mux8Way16 without incorporating the Mux4Way16 the first couple of times I made this chip. Whatever the reason it was only the third time I made this chip that the penny dropped about how to build them using simpler ones. And once that happened I saw then how it was possible to do so for DMuxs too.
By contrast it was obvious that it would not be possible to build the big RAM chips without using smaller ones as the building blocks, at the same time though it seemed obvious how to do it.
I think that Muxs and Dmuxs are harder to visualize at least for how my mind works
I think that Petzold's book complements yours for its very good explanation of the parts (Nand, DFF) that TECS treats as primitives. I don't think I would have been happy to not understand how these work.
I recommend a website that enables the user to construct (eg DFFs, even 8-bit memory) from logic gates.
Petzold's book tells you how and this website allows you to do it.
Currently as I said I'm on chapter 5 which for me is a leap in difficulty over the ones before it.
I may well end up looking for help on this forum so it's great to see it here.
Anyway I think TECs is marvellous and I am very grateful to its authors because I have learned so much already and am looking forward to learning more, however slowly!