PMNW had more non stops into Asia somewhat earlier. For example, I remember taking MSP-HKG, JFK-Osaka (to the international terminal in the old airport), someplace(maybe DTW)-KIX, but of course then there was nothing to China. Maybe about ten years before the merger, they started emphasizing the NRT hub more. There were more Asian destinations at that point that did not require partner operated flights.

The obvious disadvantage of going through the NRT hub is that it forces late evening arrivals and early morning departures for the longer intraAsian flights, which of course see very little O&D traffic as a result, although DL married segment inventory controls can IME make the fares high on these segments.