I worked at an airline that seperated LC and SC. Basically, the LC was #1 to be called for any trip and SC #last. That makes LC very uncommutable and SC just as uncommutable.

The current system is probably as close a system as I can think of that would allow things to be even among all reserve pilots while allowing there to be a maximum number of regular lines with minimal reserve. More regular line pilots means more white slips which replace the number of required pilots overall which probably is reason the company would never want to split LC and SC up.

---
Did you guys see Air Tran opened a second pilot and FA base in MKE? If its already been mentioned then forgive me, I was too lazy to look.