CAS' comments on this are interesting:
RUSI Lord Trenchard Lecture
This level of adaptability is provided by the Tornado’s innate design and configuration concept, which highlights the dangers of relying on more limited, niche capabilities, narrowly configured for one type of warfare. For example, it has been argued that a small, turbo-prop, aircraft would provide a cheap attack capability in Afghanistan. But its utility, and arguably survivability, would be markedly reduced in comparison with fast jets, such as the Tornado and Typhoon, because of increased vulnerability to less sophisticated enemy weapon systems, their reduced speed would limit response across the battlespace, and their more limited weaponry options and payload would reduce the deliverable effect at the precise time and place they were most needed. More importantly though, any such aircraft could not be used in other sorts of conflict with any confidence in their survival, such as when our Tornados and Harriers were called upon to operate against highly effective and integrated air defence systems in the Balkans and Iraq. Our relatively small size means that we simply cannot afford to implement specialized procurement strategies that establish force elements that are appropriate only for one sort of operation; the risk is that we end up equipped to fight the last operation or war and not the next.