The 故, which certainly seems to be wanted here, is omitted in the T‘u Shu.
avoids an army when its spirit is keen, but attacks it when it is sluggish and inclined to return. This is the art of studying moods.
The T‘ung Tien, for reasons of 避諱 “avoidance of personal names of the reigning dynasty,” reads 理 for 治 in this and the two next paragraphs.
30. Disciplined and calm, to await the appearance of disorder and hubbub amongst the enemy: — this is the art of retaining self-possession.
31. To be near the goal while the enemy is still far from it, to wait at ease
The T‘ung Tien has 逸 for 佚. The two characters are practically synonymous, but according to the commentary, the latter is the form always used in Sun Tzŭ.
while the enemy is toiling and struggling, to be well-fed while the enemy is famished: — this is the art of husbanding one's strength.
32. To refrain from intercepting
邀 is the reading of the original text. But the 兵書要訣 quotes the passage with 要 yao1 (also meaning “to intercept”), and this is supported by the Pei T‘ang Shu Ch‘ao, the Yü Lan, and Wang Hsi’s text.
an enemy whose banners are in perfect order, to refrain from attacking an army drawn up in calm and confident array:
For this translation of 堂堂, I can appeal to the authority of Tu Mu, who defines the phrase as 無懼. The other commentators mostly follow Ts‘ao Kung, who says 大, probably meaning “grand and imposing”. Li Ch‘üan, however, has 部分 “in subdivisions,” which is somewhat strange.