I'm surprised you don't like the idea of surface or target because if I remember correctly, both of us were in line on the matter when Larian implemented Chromatic Orb.
Dunno ... maybe i was and noticed this flaw a little later, but since i did, im completely against any automatization ... i believe that player should have full control over their actions.
When i want to attack an enemy, i want to make sure i will attack enemy, not create surface around him/her/them/it ... maybe im just super clumsy, but it happens to me often enough to be anoying.

It is pretty clear in game though.
If you have a %to hit it's that you attack a target. If you don't you are targetting the ground.
Of course the system is not perfect and that is true for all spells. Sometimes you click to create a surface, the UI makes you think that 2 characters are in the area of effetct but finally none of them are... The circle under characters is changing as if they were in the area of effect even if they are not. That's something I noticed while doing tests with arrows.
If I'm not wrong, if the radius indicator of the AOE is not in the middle point of the circle under characters : they are not in the AOE. That's something I should try a bit more and report.