I don't really think Osric would favor any one of his Pokemon over the others, since he identifies with each of them in one way or another. Charmeleon shares his fiery spirit, Marowak his lonely past and resulting protective streak, Umbreon his love of the night and sneaky backstabbing underhanded tactics, Zangoose his instinctive drive to put down vipers and serpents, Milotic his heart of gold, and Pachirisu his mischevous personality.
...he'd probably end up as some force of law enforcement, private security, or P.I.