The first table lists Asian regions such as UAE (Doha), Korea (Seoul), PRC (Hangzhou), and India (Mumbai), and the author has classified examples as Middle East, India, China, and Southeast Asia.
South Korea belongs to East asia, not a Southeast Asia by all means, i.e.geopolitically or ethnically or culturally.
In South Korea, it is considered offensive and rude to treat Korea as a Southeast Asian country. It's like treating Japanese as Koreans and Vietnamese as Chinese.
Also, the NATM method that Koreans have used on the Sin-Bundang Metro Line is much more cost-effective than the open cut method.