Folks, I'm flying from YYZ to VVR (Air Canada, N class) to HKG (Air Canada, K class) tomorrow, and then coming back from HKG to PEK (Air China, V class) to YYZ (Air Canada, A class). I'm wondering what's the best way to maximize my mile earnings. I have both Aeroplan and UA Mileage Plus. I have 10,000 status miles with Aeroplan, and nothing with UA this year.

YYZ to YVR is N class, so I only earn 50% on AC and nothing on UA (if I read their respective sites correctly). YVR to HKG is K class, and I earn 50% on AC and 100% on UA. HKG to PEK is V class, and I earn 50% on AC and 100% on UA. PEK to YYZ is A class, and I earn 100% on AC and 100% on UA.

Any suggestions? Should I use AC or UA? OR... can I do AC on one segment and then UA on another segment? Is that even possible? Like, when I check in, I don't register any frequent flier number. But I enter my flights back home, and switch AC-UA depending on the segment?

I would appreciate any thoughts. I was AC Elite last year, but had limited flying time, so I want to try to get back to 25k this year if possible, LOL.

Thanks!