Flimsy planes don't sunk battleships, torpedoes do and this was proven in WW1. By the time of WW2, torpedoes were even better, also the planes carrying it. If you include bombers, it was obvious that planes can sink battleships and destroyers.

The article is about dismissing proven danger as being unrealistic. All you need to do is to have some radar stations (and not to ignore it) and patrol aircrafts and a good alerting system so you can raise your planes in the air. It is that simple.