That's what you need for a phalanx, because to maintain the integrity of the hoplite line, you can't have bumps and grooves, and trees and rivers in the way; it will break things up.

而是方阵作战所必备的条件,为了维持重装步兵队列的完整性,就不能在坑坑洼洼,有树林有河流的地方布阵,这会把方阵打散

耶鲁公开课 - 古希腊历史简介课程节选