Very educational thread. 30% of the time on AC my J bag did not arrive in YYZ when I flew TG or UA/AC BKK-NRT-YYZ. When it did, 100% of the time, it was one of the last off. At YVR, bag was always in the 2nd delivery.
Quite a contrast with BR (J class BKK or HKG-TPE-YYZ or YVR). 100% of time it arrived, and was always one of the first bags off, very quickly. I find it interesting that EVA is able to deliver my bags promptly and with certainty despite having similar connection time windows as AC.