The impression that I get is that they have some pretty firm ideas about what they'd like. A BA Connect captain told me a few weeks back that BMI had poached a few ERJ FO's for fast track commands. They also have a preference for existing TP guys but notice periods can cause problems in getting them. Air Taxi pilots are also favoured. All these are what BMI and Captain JB consider to have "commercial" experience. Guys who only have done aerial work such as instruction and survey type work don't seem to get the interviews. So, a 500hr PPL instructor? I doubt they would be interested.
The guy I knew who got the job had less hours than me, certainly less multi.. He did however have "commercial" experience which is something I've only just started to get.