red team training should be provided only by a professional expert, or team of experts. Those professionals should have a real-world experience along with the skill of creating mock environment for providing trainings. In all, they should be able to deal with threats effectively in reality as well as during testing.
This is possible only when the hiring of trainers is done carefully after keeping all the traits in view. The hiring experts should know that they need to choose a team of people who are physically sound, strong, active, aware, perfect in tool-handling etc. Then only the training sessions can be a success for employees.