...your final destination determined which flight you were routed on.

I used to do a lot of routings out of LAX where there was wingtip service LAX-PHX in the morning. I always noted that whichever of these flights the computer suggested, I wound on the right concourse in PHX for my next flight, although the two flights would always come into two different concourses.

When I switched to SBA-PHX for my lead legs I NEVER got an arrival and departure in the same concourse.