Picking a general from among the dwarves. (best of a bad lot - Chinese saying)
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Colloquial and a bit pejorative - 矬 lives in northern dialect. The character combines 矢 'arrow' (used in 短 too, signaling 'short') with 坐 phonetic. The famous saying 矬子里拔将军 'pick a general from the shorties' = best of a bad bunch.
Left arrow radical - pictograph of an arrow with feathered tail. In 矬 it serves as the indexing radical, evoking measurement: an arrow as a short reference length. 矢-family chars often relate to short/precise things (短 short, 知 to know - "speak as direct as an arrow").
Right 坐 supplies the sound - zuò drifting to cuó with regular onset shift. 坐 itself shows two people sitting on the earth, and that low-to-the-ground imagery dovetails with the meaning of 矬: short of stature, low, dwarfish (used colloquially in northern dialects).