I checked your Dibble's profile, looked at his game log and kept clicking until I found a game both he and Orosco appeared in:
Dibble came in first.
I also see Dibble's been under 100% most of the season. Is it possible Orosco's only coming into games first when Dibble's on autorest? Have you seen Orosco come into a game first when Dibble's available?