Originally Posted by
ellinj
I have read it several times.
For ARN-LHR-LAX, If EQMs are what you are after it actually doesn't matter, AA coded flights earn 1.5 EQMS in PE; same for BA, As far as I understand it, this isn't always the case, some business fare classes earn more EQMs as AA coded flights. It is true that for RDMs the BA flight numbers should yield you more total miles.
OP needs 2k EQDs in addition to the EQM, so BA coded flights are the way to go. AA flights would earn around 900 EQD, while BA would earn 2,300.
Really not sure what the confusion is here...