This is due to how Atlas completes IOE and initial type ride training. At other airlines IOE is part of the entire training process. Instead Atlas separates the type ride from IOE. IOW you'll complete your type ride and then bid for when you want to fly after your type ride. if you don't match up with an LCA then you don't complete your IOE. Also, there are so many changes to schedules that even when you are paired up with an LCA the likelihood of staying matched to that LCA is minimal. Hence it takes a long time to get matched up with an LCA and once you are finally matched up they'll rip the LCA away for another trip and leave you stranded.