Probably don't need to point out on that EY/NH fare CAI-NRT-NGO, there's absolutely no need to take the last flight. Japan, like many countries, you'll fully clear in at NRT and can just walk out of the airport there and skip the domestic flight. If you're not after OneWorld miles/status, EY is light years better than RJ all around.

The MU one is certainly a cheap way to get to the middle east to pick up one of the ex-CAI, AUH, or DOH premium deals floating around. I'd be surprised to see any non-mainland carriers match that, usually pre-pandemic no one else did despite MU and CA leading the way in MANY different business class promo fares. MU actually has a really solid suite product now but I believe it's only on the A350. The 77Ws and one version of the A330 though have very acceptable seats. Not sure which configuration they run on the PVG-DXB route.