When buildings are too close together enemy troops can't be deployed between them. How do you tell when they're close enough? I built a wall around my main base (including town centre) but attackers can still deploy troops within the wall.
For ascetic reasons I like having my village spaced out, it's too bad that the game play promotes against it.
Here is a screen shot while in edit mode. I have the town hall selected and moved it around a little, but still there are no lines to indicate where attacking troops can't be deployed. I notice there are some white lines outside the walls, but those are different, for example with this current setup I've had enemy troops deployed within the walls.