Well, GSL has no problems still using Jacky even after he went to ESV. There's a definite difference in Korean and foreign mapmaking styles. Semmo even though on Crux has a more foreign style and I've never seen his maps in the GSL. Is Semmo a Korean or speaks Korean?

The reason GSL doesn't use foreign maps too often might be a stylistic thing. Koreans like their circle syndrome, foreigners don't.