The reality on banks like this is that they are very hard to manage. There are specialists in every corner, and somehow the head of the bank has to keep tabs on all of them. Almost always, the money makers outearn the risk managers and compliance folks, so it's a game of catch-up. (Any bank that flipped it would go out of business - like the one honest used car salesman would.)
It depends on your point of view. Too big for what? Big can come in different manners. # of people to watch when 1 or 2 can cause trouble. Size of assets. # of distinct businesses. Size of risk position. Size of counterparty risk.
