The four cannon barrels can change the direction to some extent and pike after pike were being shot at the Sea-Hawks.
There is a reason why they didn't choose explosives and impact shells to shoot.
It's because there is a high chance of getting damaged by them. If the opponents just tried to use some methods that could block their ascent and let them fall down back on the ship, the results would be disastrous.
Rather, these metallic pikes are a good replacement for that.
They are mainly focused on damaging a single entity rather than an area of effect damage. On top of that, they could also integrate any form of spiritual energy into them and have different properties when they attacked.
The fire element can cause an explosion of flames, the wind element can form a sharp wind blade, and the earth element or metal element can form a crushing brute force. All of them are possible.