Antonyms for the colloquial expression "ran a tight ship" are numerous, and include running a lax, loose, or sloppy operation. Someone who "runs a tight ship" is generally considered to be organized, efficient, and strict, whereas the opposite behavior may be seen as disorganized, slow, or ineffective.
Alternatives to "ran a tight ship" could use language that emphasizes risk-taking, flexibility, or creativity, such as "ran a dynamic enterprise," "led with an open mind," or "created a fluid workplace." Other antonyms for the phrase might include "ran a tumultuous crew," "led with a laissez-faire attitude," or "maintained a chaotic atmosphere.