When we describe something as "most hairsplitting", we mean that it is overly precise, nitpicky, or overly detailed. The opposite of this would be to describe something as "general", "vague", or "imprecise". If we want to emphasize that something is not subject to meticulous attention, we could use terms like "flexible", "loose", or "broad". A good example of an antonym for "most hairsplitting" might be "big picture thinking", which refers to taking a broader view of things rather than worrying about specific details. Other antonyms might include "relaxed", "laid-back", "casual", "informal", or "nonchalant".