The expression "like a one-man band" refers to a person who is capable of doing multiple things simultaneously, essentially functioning like a self-sufficient whole. Antonyms for this phrase include "dependent," "inefficient," "inept," and "incompetent." These words suggest a lack of organization, cooperation, or skill, and convey the idea that the person in question is not able to function effectively without help or support from others. The opposite of being a one-man band is working collaboratively with others, delegating tasks to adept specialists, and relying on team members to contribute their unique skills and expertise to achieve a common goal.