Your idea is correct, but I can guarantee you that as an anti-hog base, this design will fail. The problem is with your core. It's too big. There are instances where as the hogs are going around the outer ring, the next closest defensive building will not be in the outer ring anymore. It will actually be in the core. Then once the hogs breach the core and have a healing spell to protect them, your base will be overrun.
Remember, when trying to determine where the next closest defensive building is, you can't count tiles based off of the middle of the defensive structure, it's actually based off of where the hogs attack from, so either the left, right, or outer side of the defensive structure (not the middle/center).
Essentially, you need more space between your outer defensive layer and your core.
Your core is too big for this to happen. Shrink your core, create a larger middle "buffer" layer. Good luck!

