Have I said anything different anywhere else?
You said this:
The PADI coruses can be combined all you want, but they have to be taught in sequence. That is the big difference between the TDI program and the PADI program--they are designed completely differently. TDI teaches Advanced Nitrox in one course, and it teaches decompression procedures in another. The only way you can teach them in a meaningful way is to combine the two course and and have the instructor rearrange the lessons and skills in an order that makes sense sequentially. The PADI program combines the learning of the concepts in the course sequence, so it is already structured in a way that makes sense sequentially.
This makes it sound like the normal thing for TDI is that AN and DP are taught separately. They are not (normally). Even though the student gets handed 2 (or 3 or 4) physical books for the class and they get 2 (or 3 or 4) individual C cards at the end, FROM THE STUDENT'S PERSPECTIVE, it is one class that happens to use 2 (or more) books.
The way you insist on continually describing it is, in my opinion, very misleading for anyone who is thinking of taking the TDI tech courses. From the student's perspective, it is one class. They pay one fee. The get some books and maybe even some additional books or other materials to read beyond the official TDI ones. They do the classroom. They do 6 dives (unless the instructor decides to require more). And they are done.
Insisting on representing the TDI tech courses (for AN, DP, and Helitrox) as multiple courses, to people who are simply seeking information on what tech courses they might take, is misleading. From your instructor perspective, it may be 2 or 3 or 4 courses that you have to decide how you want to present. But, as far as the student is concerned, it's just one course. Plain and simple.
It's like you are purposely trying to skew the perception of the TDI track to make the PADI track sound better. When, in fact, if it's a good instructor, it will be a good class, whether it's PADI or TDI. And if it's a bad instructor, it will be a bad class. So, for a student, it seems to me that the real discriminator is that PADI has the track broken down into 4 or 5 classes which, as you say, must be done sequentially. TDI has it broken into 3 classes. For some students (like me, for example), that makes the TDI track preferable because it was more efficient for my time and my money.