Bhagavad Gita, Chapter 18, Verse 47

Better is one's own Dharma, though imperfect, than the Dharma of another well-performed. He who does the duty ordained by his own nature incurs no evil.

Your own duty, done imperfectly, is better than someone else's done well.

Krishna doesn't measure this by outward performance, he measures it by fit with one's own nature. Authenticity, not flawlessness, is what matters here.