Just wait until you get queen bess then. Have a gunnery wight supporting her with the more powder action to keep it firing. Remember Bess is unlocked via ritual then recruited via regiment of renown tab (just in case you weren’t aware).
I generally have Bess and a couple of other mortars together with a wight and that does enough to weaken the front line for my meat shield to slow and ultimately tarpit the attacking force. I don’t care about friendly fire with zombies, they’re expendable.
Also with their combat skills levelled up, a gunnery wight becomes a very strong ranged attacker in his own right.
Yes you want land as Noctilus, but when it is land you can’t keep then sack and pirate cove and move on. That’s generally best for places where there is low vampire corruption.