John, you make a good point. One of the initial conerns Ken Matzick raised when we wanted to use mid train helpers on a long train out of Antonito was whether the engine crews would be able to handle the situation. Running a helper in the middle or on the rear end of a train requires specialized skills that are not used in passenger service. That's a concern even today on the main lines. CSX publishes an instruction booklet specifically for employees in helper service.
Another is dealing with derailments. This doesn't happen all that often in passenger service, but when it does happen, knowing how to properly (and quickly) rerail a car is vital. Derailments are more likely to happen when switching freight cars and while nobody enjoys lugging those heavy rerailing frogs back from the engine, it's a useful skill to have.
Michael Allen