Sorry to see no one has bothered to give you a quick reply but it appears you do not have a full understanding of cadet pilot programs (CCPs). These are run by the airlines for people they have already accepted, so you know you'll be working for them even before you start.
However, most start off not in CCPs but in flight schools which are not affiliated with the airlines and then go on to instructional or charter jobs to build hours. If you do a self-sponsored scheme at a CCP school then understandably its airline cadets will have priority for competiting resources (aircraft, instructors etc) - a strong reason for not joining CCP flight schools if you are self-sponsoring. Some CCP schools do not accept self-sponsored applicants at all.
My advice to you is to do some thorough research in the DG&P forums.