There are several synonyms that can be used in place of the phrase "falls in line." One such word is "complies," which means to obey or follow rules or orders. Another synonym is "conforms," which means to behave in accordance with established norms or standards. Other synonyms include "aligns," "cooperates," and "adheres." These words all suggest a willingness to work within a system or structure, and to follow established guidelines or protocols. When someone "falls in line," they are essentially agreeing to operate within certain parameters, and to do what is expected of them. It's important to choose the right synonym to convey the intended meaning and tone of a sentence.