When the Tutor was selected, I think that there were 2 propellers available - made by Hoffmann or Mühlbauer. With a similar 3-blade, composite, variable-pitch Hoffmann in use on the Firefly, it would have seemed a reasonably safe choice. If, as it seems, there have been 2 similar failures after 13 years and some half a million hours of use, that is a trend that would have been difficult to predict at the start.
The Bulldog replacement had to meet a specification to satisfy the needs of air cadet AEF (by far the largest number of hours), direct-entry EFT (much of it for rotary pilots for all Services), UAS training, elementary navigator training, multi-engine lead-in training and the first stage of multi-engine QFI training. Of the aircraft then available, this aircraft, specially tailored to cover all aspects of the task, presumably offered a logical solution, even if not the most outstanding first aircraft for RAF fixed-wing pilot training. The length of the original PFI contract should have allowed UK MFTS to start with a clean sheet of paper, with piston, turbo-prop and jet options as a first stage.