For chin na to work, you must concern yourself with the underlying principles rather than technique.
Once you understand how the principles work, you can use them spontaneously in accord with the requirement of a given situation.
This is more realistic.

Adaptation is essential; you change what you are doing relative to what is happening.
If your chin na is countered by your opponent, you move into a different one or adopt a different strategy entirely - such as stepping or striking.