What I am saying is that I believe that one can improve one's knowledge and then skill and then ability by understanding the roots of where one's martial art come from.
From a practical POV, different exercises and methods from different traditions tend to isolate principles in different ways. Speaking about body use that is. If you can trace what you do, you can get a clearer appreciation of different mechanics and body use from older exercises.
The problem with an art as Tai Chi is that it's so darn complex. There are layers and layers of methods and mechanics from many different exercises and traditions that have melted together. And then later, the sum of what's in this pot is in turn interpreted again in other, new ways.
What is contained in Tai Chi movements? What do you need for tai chi body mechanics?
- Deep core leg strength
- Understanding how to use and open the kua
- Use of Dantian
- Use of deep breath
- Use of lower ribs
- Use of spine
- Use of scapula
- Whole body coordination and understanding of the six correlations (Liuhe)
- Understanding of kai/he
- Understanding of "pre heavenly principle" of movement
- Understanding of mind, yi and shen
- Coordinating breath, mind and body.
- And more? (what did I forget?)
You really need individual exercises for each and one of these things listed above. You need to isolate and practice different principles separated and then again different ways to put them together.
But Tai Chi practice today normally doesn't have individual sets for everything, so if you can't get what you need, it's good to borrow exercises from Tongbei, Bagua, Shaolin and others. Also remember that "style" and "systems" is modern invention. In older days different forms and exercises had names, but not systems of exercises. They were not that fixed. In earlier days, this was how martial arts were practiced, not as isolated systems, but by practicing different, related exercises from here and there.