The designation of the seat doesn't matter. If there was a requirement for the pilot to be in the left seat, it would state so in the AFM (think Piper Cub requiring the pilot sit in the rear seat for solo flights).
Even Cessnas term the left seat the pilot seat and the right a passenger seat. Doesn't stop plenty of instructors from sitting right seat, or you or I from just hopping in the right seat and going flying.
Plenty of 135 ops that do in-aircraft training for typed airplanes with the only typed pilot sitting in the right seat (Metros, 1900s, etc). Flyright and Simcom I believe both offer in-aircraft training for typed birds.