Customisable defence lines

At times it can be frustrating making defense lines because you're restricted on how they automatically form on the map.
So, the same way you make borders in map editer by simply clicking and dragging any part of it and customizing the borders any way you like should be the same for defense lines.

It will make less of a mess and everyone can be very effective and accurate with their own play styles. This could be a core game mechanic or a start.

Other custom ideas(off the top of my head here)
Two starts;
"Stronger defense lines at the cost of..." Could solely focus on defense and vice versa?

"Better defense/attack in defense lines if it's solely made by defensive or offensive units"?