Mortars next to each other?

Which is better? Next to each other or the other one farther away but not to far they cant protect each other.

 

I prefer closer, but I think it is a matter of opinion. As long as something covers the dead zones

 

I like them to overlap when I came, but two mortars right next to each other aren't. The dead zone close to the mortars is too much of a liability. Have a close attacking unit between them in the very least