Devs say defense buildings provide 5% more plunder. Remember though each building provides it's own part to plunder. So the part it gives is 5% more. So let me give you an example: You have 25 lands with a build of 1 castle, 23 circles, 1 titan. With one unload you get 1B (just to keep the math easy). So with that 1B each building gave 41,580,041 gold. But the Titan gives 5% more, so it actually gave 43,659,043 gold. This is 2,079,002 more gold. But is only an increase of 0.208% of the total gold. You need to unload 481 times to make 1B gold from that 0.208%. Assuming 12 unloads per day it take 40 days to make 1B from that 0.208% So is having a Titan really useful? I think not