Use "damage per second" instead of just "damage"

That's the whole thing with all pirates and defenses in the game: they aren't properly communicated so the player has to find out everything by trying them out. Of course you need to try things in practice to learn the best way of using troops, but a game like this needs the stats to support the decisions and the learning process. Now the game fails at it pretty badly.

 

Your analysis is correct for the gun tower vs a single unit, but the gun tower has some advantages when it comes to multiple units, somewhat like the mortar. In fact if you use your same analysis on the mortar I think you would find that "you should only ever build them when you have exhausted all other defenses" which is clearly wrong.

Since the different guns shoot at different enemies, the effectiveness of your tanks is reduced, unless you have at least one tank per gun. The gun tower also is unable to shoot at a melee unit attacking it, freeing all three (or both) guns to fire over their heads and take out gunners. The result is that a gun tower combined with a cannon is much more effective than either of them on their own.

 

Good point with the tank. Didn't think about that

 

+1 good idea