By training brush writing alone one could develop a feeling how a certain brush stroke was created, see the movement of the brush during the moment of the creation. The movement of the creation is frozen in the marks the brush had made by applying the ink on to the paper or silk. The value of the calligraphy is this movement itself not the result. The written character in the art of calligraphy is the vehicle which allows the connoisseur to relive the moment of creation.
The writing is the masterpiece, not the written.
So if the movement failes there is no meaning in cheating. One would have to start over.
The bigger the characters the more creative genius is needed to keep the balance. Or the smaller the characters the more essential it becomes to train the creating movement of the brush again and again.
All this is valid as well in painting too, but now of course the strokes are much freer and have to create the structures to form the painting.
The special calligraphic character of each individual brush stroke creates then movement in the painted subject. So if there is hesitation in the strokes there will be hesitation in the painting. The size of the strokes or whether they are done in ink or colour does not matter here.
Power which had moved the brush then could transform in the painting into power that shows actual movement, power that shows potential movement of resting objects, or even gone power that led to the form now depicted.
Lets start with a few examples of a painting done in a very simple style, just so that the quality of brush strokes is revealed to the connoisseur. With just very few strokes an old plum tree is sketched from which fresh brunches grow out, a few flowers.