In my NH class at AAL we had 5 UAL, 2 DAL, and 2 SWA pilots. It was a class of around 60. I vaguely remember when each of us introduced ourselves to the class, all except 1 SWA gal was inside 1 year.

It doesn’t matter how many leave one for another. If UAL is your first choice and you have a CJO it would behoove you to make your decision quickly. All 3 are hiring over 200 a month.