I had the same experience at Citibank. We started at a small branch in downtown LA with our Series Seed round check for $3M. Even then we barely got any attention, and dealt with just a local branch manager. Later we closed $7.5M, still no attention; except this time due to consolidation we were kicked to a regional team that handled our account as a team. In fact we never had a dedicated banker, we were just handled like so many SMB by calling a banking center. Over the years we asked for things like corporate credit cards and the like, but it always seemed we were just a little too small (I guess with Fortune 50 clients, we were small to them). Anyway we eventually moved to a smaller independent bank for different reasons.
His conclusion is sound while yours is not. Korean is not a dialect of Chinese, which seems to be your implication. Neither is it a "branch" of a tree of which Chinese is the trunk. In linguistic terms it is called a "language isolate". In the past, linguists tended to group Korean and Japanese together; I believe largely for political reasons they have been separated--but that's another topic.
Korean uses many Chinese loan words (in the same way that English uses Greek loan words) but the sentence structure, pronunciation and grammar are totally different. You would not say English is a dialect or branch of Greek for the same reason.
I speak both Korean, Japanese and am currently studying Chinese. Korean does not sound like Mandarin at all because it is not a tonal language. It does sound similar to Mongolian and Manchurian. That is not surprising because the roots of Koreans (and probably their current language) come from the area north of Korea near Manchuria.