The word "insubmissive" itself implies a lack of compliance or obedience. So, its antonyms would be words that reflect submission or obedience. Some of the antonyms for "most insubmissive" are compliant, obedient, submissive, docile, yielding, meek, tractable, deferential, and subservient. These words suggest an attitude of acquiescence or conformity, rather than resistance or defiance. People who are compliant or obedient are easy to manage or control, and they exhibit a willingness to follow orders or instructions without question. In contrast, those who are insubmissive or disobedient may resist authority or challenge the status quo, which can lead to conflict or tension.