I can't tell you which ones, but most economy BA fares earn only 25% of the actual miles flown regardless who they're assigned to. The only way to earn 100% of the AA miles plus any status miles in cheap/discount economy is if the YVR-LHR has AA codeshare AA flight # and that's the way you ticket it.
This would have been a better post on the AA or BA forum. Just give it some time and I'm sure the moderator will move it.