The phrase "most hair splitting" is often used to describe a situation or argument where someone is being overly nit-picky or overly critical. Some synonyms for this phrase might include things like "overly meticulous," "unnecessarily detailed," or "hypercritical." Other potential synonyms might include "overanalyzing," "overthinking," or "excessively focused on minor details." Ultimately, these words all convey the same idea of someone who is too focused on small details and may be missing the bigger picture. Whether you are trying to describe a colleague at work or simply trying to find a different way to describe your own tendencies, these synonyms for "most hair splitting" can be useful tools.