[fnordpiglet]

Both Newton and Leibniz intersected with calculus but had incredibly diverse careers spanning many subjects that were totally orthogonal. So, no, in fact the fact they discovered calculus in very different ways proves the point even further - they were so singular as to arrive at similar breathtaking insights from totally different perspectives totally independently, for the first time in all of mankind. You can’t substitute one for the other, and each was totally indispensable and irreplaceable.