It is very unfortunate that Hegel achieved superstardom and Schelling ended up half forgotten.
If you compare them on purely cognitive capacities, Schelling was a much greater genius. Schelling was actually one of the smartest men that ever lived, he was on the same intellectual level as Plato, Goethe or Wittgenstein.
Kant started a new revolutionary way of doing philosophy that we now call german idealism. Fichte got rid of the thing-in-itself, but for him nature became a dead byproduct of the ego, nature is just not-ego that limits the ego. Schelling rightly disagreed with Fichte's wrong approach regarding objective reality and brought nature back to the central stage, but he appealed to the notion of intuition epistemologically. In other words, we can understand the deepest truths about nature, but not rationally, it can be mystically revealed to us in a religious like state, but not scientifically or systematically. Schopenhauer agreed with this and he also believed that the will (the Kantian thing-in-itself) cannot be known rationally.
Hegel thought that Schelling was on the right track, but the project is far from done. He thought Fichte's criticism of Kant and dialectical approach to philosophy is correct, and Schelling's dynamic unfolding of nature is also correct, but Schelling's thesis that nature is fundamentally irrational (thus not logically systematizable) is wrong. Hegel completed Schelling's project by creating a philosophical system.
So to answer your question: Hegel is more important than Schelling because of where he stands in the history of german idealism. Kant started it, Fichte and Schelling advanced it, and Hegel completed it. The guy who brings everything together always gets the most credit.
Interestingly, if it wasn't for Heidegger's interest in Schelling, the latter could have been totally forgotten by now.