FWIW, the single DL internal Rec of mine ( an FO) said that you really only need 1 internal rec for an invite, not sure if that's true or not, or what the magic number is, but obviously more wouldn't hurt.

For those submitting external recs (both professional/personal), are you using the airlineapps.com link through the addendums page to send the request? Are the external recs even relevant or reviewed prior to receiving an interview invite?