Zhou Hanyu was busy adding color to the hero design draft.
Before developing League of Legends, Zhou Hanyu had hired a few more people, including an experienced original artist, two UI artists, three 3d stylists, and two action artists. He had basically set up a small art team.
In fact, based on the situation with Warcraft and Diablo, the art could be outsourced, but it would be more expensive to communicate and slower to do.
However, Chen Mo considered the fact that he would have to produce a large number of character concept art and models in League of Legends, including new heroes and new skins. It wouldn't be good to outsource too much, so he wanted to build a small art team first.
Moreover, Chen Mo now had a lot more money for research and development, so he didn't feel any pressure supporting an art team.