I don't see anything wrong with training in the aircraft, surely it must be safer doing it in an emb than a chieftain?
I suspect this comment came from some one who has not had the opportunity to train in a sim?
There is absolutely no comparison. It is simply impossible to practice most scenarios in an aircraft.
The difference between a cheiftan and a larger aircraft is that there are no cheiftan sims, and we aren't talking about those flight sims.