Now if SWR has lost 18% of their operations, unless they have seen 18% of staff retire or leave (and not be replaced) in 5 years, then not having surplus staff for training suggests something else is delaying training.
It doesn’t necessarily mean that. Retirements, training paused and stopped for a period during Covid. Plus you don’t know how those numbers break down between depots. It isn’t as simple as saying 18% less operations = 18% less staff required.