It is not a proverb but it could become one, it has the necessary quality. This is the answer that Constantin Brancusi gave when Auguste Rodin invited him to work and improve in his studio. Hints: great oak, weeds
Je propose, sans recherche, en m'appuyant sur le hanjie : "Le grand chêne pousse toujours au milieu des mauvaises herbes."
In the shadow of the great oaks grow only weeds