Effective calculation of attack position?

[slogic]

One of the future big improvements of E323AI could be calculation of attack position considering its weapon AoE (scouts & artillery will gain much from this algo). Currently attack position it the position of the target. This is simple because target is placed on proper path already and we can reach it.

For now i'm thinking of iterating points on a circle around target position with some angle steps: 30 degrees. Radius of circle equals to AoE. So i need to scan 12 points. I have to select the most safest & reachable among them. Last one is too expensive and stops me from implementing this. Calculation of reachability from target position is not valid because target can be on the water, and attack group is the land group only.

Is there some info i can read to implement this effectively? Or even better: to steal from somewhere?