Crab - you are correct and it is an ideal. It works well in the military. I saw it myself in my time and all the staff used in the sim were excellent instructors and former squadron QHI’s.
The main difference is that in the military environment you have time to train in the aircraft and a large amount of budgeted training sorties. Here the Squadron QHI can have his input on the process and feed down the directives from his boss. That does not exist in the offshore world. There are no dedicated aircraft training sorties available after the initial aircraft famil following the type rating.
If an operator were to wholeheartedly embrace third party training they must be able to address the shortfalls. I think the way it is done in the military is an excellent example of how it can work. The key is the two systems must work closely together and be on the same team. An operator cannot just let go of the ropes and say goodbye to training - “third party provider - you have control”.