I don’t think it would hurt to have a barrier or two added to the flow. Like a training record review or a look at a personnel file. Probably way past time to go back and change that process...
Anyway, toward the end of my stint on the 190 a captain told me the following story: He had been hired by Airways from Mesaba. When he was at Mesaba a captain there had been, allegedly, drugging and sexually assaulting flight attendants. Crazy story today, back then he was allowed to resign. Fast forward to this 190 CA showing up at the CLT training center for an R9 and guess who’s strolling around... the guy now works for PSA and gets to walk in the door at AA.
The flow serves its purpose in many ways. It alleviates the pressure on HR to interview and hire an enormous amount of pilots and acts as a recruiting tool for the wholly owned regionals. If it was causing a giant headache for AA they would change it.