Why would there would be a fight for control, I would think that the Captain would be more shocked that his presumptuous FO has taken control than anything else. In that state of initial shock I believe that the Captain would initially just let the FO fly. There would most likely be a bit of heated discussion later and the Capt would demand control, but all the FO is trying to do is to upset the train of events from happening. By starting a go-around you would hope that the capt would continue the MAP and come back for a second attempt.
How did the FO know that his captain wasn't subtly incapacitated incapacitated, the fact that he is awake and flying the aircraft doesn't mean that he is in control of his senses. Surely a pilot who is approaching very high and very fast and not in the landing config, so far out of the slot that it is not funny, displays a complete lack of situational awareness would start to ring alarm bells with the FO.
This comes back to the crux of the matter, loss of face. How do you train asian FO's to have enough balls to take over in life and death situations. Western airlines seem to be able to do it.