Appropriateness is about the when and the how.
Applying all your strength against a stable, rooted, prepared opponent is not
smart.
Force against force is not taijiquan.
You must learn to be subtle. To be sensitive. To listen. To feel. To
yield. To
trick your opponent's nervous system.
The application of 13 postures depends upon your ability to apply your strength
at the right moment.
If you get it right, 4 ounces of pressure will be all you require.