Bridge Building & Improved Positions

[Liebchen]

It occurs to me that engineer units making a bridge should not be benefiting from the protection of earthworks in their hex, and especially not bunkers or stronger. They are likely as exposed as can be, especially in a non-marsh or -swamp hex.

I mean, guns can only be protected if they are deployed (makes sense), and (deployed) vehicles can only take advantage of earthworks but not pillboxes or forts. So bridges that are under construction, be it a structure, a set of pontoons, or a causeway of some sort, would be right out in the open.

Any thoughts?