To update and prolong the life of Merlin Mk3 costs money, and gives capability. To buy more CH47 costs money, and gives capability. To prolong the life of SK4 costs money, and gives capability. To not spend money, you have to lose capability. Whether the decision is correct can be debated for a long time. In reality very few people have access to all the costs and capability assessments. But I hope we can agree that it is better that something happens rather than the cheapest option of do nothing and gradually remove the SK4 from service with no replacement. Or is that naive of me?