I always say opponent not stupid. This is why we study game plans and probability so that we understand how to apply our Tai Chi Chuan techniques better. However, this does not require us to delve deeply into academic theories, just a working understanding of what it means.
At a certain stage of learning a technique is just a physical movement. As you progress in your ability to apply the technique the movement then becomes more than just a physical movement. At this stage it becomes an expression of the strategy you want to apply, your mastery of letting go, to go with the flow, to elicit certain reactions from your opponent that will facilitate your implementation of the technique etc.
When you understand this you don’t need to expand your repertoire of techniques. If anything, you will find that you can do more with less.
Its my theory that this is why the original 13 postures was expanded – to teach students by offering them a broader picture. However, at the advanced level it just comes back to the 13 postures or whatever are the core postures in your style. In this sense, a punch is not a punch yet a punch is just a punch. So all those crazy, nonsensical Zen talk do actually make sense once your mind clears up and you can see clearly things for what they are.