I think I understand your question, but there's no definite answer:) People use TQ in many ways. It can be a stand alone history program. It's basically a huge booklist w/biblical commentary on the major topics of history...talking about who God is and how man has responded and the consequences of that.
However, I prefer it as a wonderful supplement. I would have a hard time planning my year and staying on track w/just TQ. The booklist is so huge it would be difficult for me to narrow and finish a guide in a reasonable amount of time! That's what I love about SCM. It gives me an idea on how many books we can reasonably finish in a year. What I did last year was use mostly SCM books and pencil checked them in my TQ guide, plus added in a couple other TQ 'don't miss' books...and some of the TQ movie rec.'s. It took a bit of work to plan out my year, but was a great year. The previous year I didn't plan and it felt crammed at the end of the year to get it all done!
Next year, I'd like the planning mostly done for me, so I plan to buy the SCM guide and just write in the TQ commentary in the margin where it applies. And probably add in a few more books. I don't know if that helps any...but my opinion is that SCM and TQ work great in conjuction w/each other. TQ for the commentary, and SCM for the structure! Blessings, Gina