Without a doubt, the component that this Orange Oddity could transform into—an [External Cobalt Piercing Bullet Launcher]—is definitely an attack weapon of top rank.
Although it's just an external launcher capable of mounting only two cobalt bullets at a time, it cannot fire indefinitely like the main and secondary cannons do; after every launch, new bullets must be manually reloaded.
Also, as an external launcher, it can't be loaded from inside the warship, so in a single battle, it would generally be limited to firing just two shells.
Yet, its value cannot be denied. Without mentioning anything else, just the addition of the armor-piercing feature alone is enough to call it top rank.
Features like armor-piercing, shield breaking, and binding are extremely rare. Possessing any one of these features would be enough to classify it as a top-rank component.