Sorry, redbeard, it's unreasonable for the company to pay an extra $600 to fly your preferred carrier.
Imagine your teenage son came to you and tried to sell the same story about how he could do more studying if he flew on UA or tried to justify it based on probability of delay.
You'd laugh and tell him "Good try, son. Enjoy Phoenix" It's all different when it's OPM (Other People's Money).