China's ambitions in the South China Sea along threatening Asean nations Philippines, and Vietnam are understood in a bipartisan way as a very high risk flash point for the start of a big war with China. So yeah, he revealed his great ignorance not knowing what Asean is.
Taiwan of course can't be in Asean for obvious reasons.
He's simply not qualified period.
As Jake Broe conservative republican veteran has commented -- in every meeting he's going to be the DUMBEST person in the room. Trump is very reckless pushing nominees like him for such vital war and peace, life and death, leadership positions. Trump obviously only wants fully loyal stuffed shirts that he can boss around and play dictator. A very dark time for the USA and the world.