The first step in finding a solution is going to be get the employee groups working together instead of looking out for themselves and playing into the ocmpanyies hands.
Given human nature what it is, a seemless unity of employee groups putting their own self interest on the back burner is probably not obtainable to the degree that I think you're envisioning. I'm not convinced it's necessarily playing into the company's hands.
I would still be interested to know exactly how you think ALPA and the APA could work together and to what specific outcome? There's really no point in working together unless there are specific objectives. Otherwise it's just an irrelevant group hug. Given the contracts that they are currently locked into and the large number of AA pilots on furlough, what specifically could the AE ALPA and the APA do to compel management to effect change. Also, to complicate the situation is the varying dates of contract expiration. If you could wave a magic wand and have the APA grant you three wishes, what would they be?
As far as hiring practices go, as you infer, AMR selects the candidates for interview and makes final selection, not the union. I asked once why there was a lower percentage of regional pilots than one would expect. The answer given was that the company experienced a higher percentage of training failures with pure-civ regional pilots. However, that said, given very low overall failure rate, that is a thing measured with a micrometer and not a yardstick . . . . and statistically, mostly irrelevant, IMHO. I think with the traditional mix, the failure rate was about 2%, which speaks pretty well to the selection process. I think the real reason is there isn't a problem with training with the traditional new-hire mix, and they see no reason to change it. The other part of that is money-wise, if they hire a AE captain, they drive three training cycles vice one.