Yes I am aware of miles that can be earned per booking class (Full Economy, Discounted Economy) and I think majority of the airlines has the same percentage of accrual per booking class.

Though other airline of the same alliance might offer better options, I will just stick to JL or NH since I am expecting to fly many domestic routes in Japan using either of the two, and if ever which alliance will suit my conditions such as intra-Asia flying, access to Europe in the future, then that will be the one I will choose (sorry if I sound confusing now).

In OW, I have CX to access all Asian destinations, if *A, I have variety such as TG, SQ, UA and BR. Though like you mentioned coverage is not the measure of alliance advantage?

Ok to give you an idea of my planned international destinations, here they are as follow. Please help which alliance will suit me then I can decide whether it will be NH or JL (if *A or OW respectively)

1.) HKG (my gf currently works here so regular visit)
2.) SIN (my cousins works there now, so regular visit too)
3.) MNL (my home town, I will go during my annual leave)
4.) YVR (planned destination in the future since my gf will work there)
5.) IBZ (my wanted destination in the future)

plans also for other Asian destinations such as ICN, TPE, HAN.

And future RTW.