This underestimates the requirements. It requires sophisticated real-time terminal guidance. This is not a cheap feature. Modern anti-ship drones dynamically select a precise point of impact based on their observation of the target to maximize probability of hitting a vulnerable spot. Especially with a weak warhead like the Shahed, most points of impact would be scratching the paint.

The model you are talking about was basically how things worked in the 1970s. Technology has improved a lot over the last half century.