SQ and CX are famous for changing aircraft (and seats) used for a regional Asia flight at the last minute. On my CX flights between HKG and SIN, TPE, ICN, NRT and HND, I've had their entire range of aircraft and seats. CX just puts an available aircraft on the regional Asia flights and doesn't really care what sort of seats it happens to have. In my last 4 CX HND-HKG flights, I've had a A330 with new seats, an A330 with old seats, a 747 with old seats and a 777 with new seats (in fact, that 777 HND-HKG flight used the same aircraft I boarded 3 hours later for JFK).
JL has been adding new config aircraft to HND flights just as much as to NRT flights. The aircraft on their TYO-SIN flights rotate between NRT and HND via SIN.
There are more long haul flights to NRT, so there are more long haul aircraft through there. Doesn't mean HND is getting a lower product.
BA uses 77Ws to NRT (14F/56J/44W/183Y) and 772s to HND (12F/48J/32W/127Y)