I am developing an RTS-like game, that have units that move and attack. I implemented path-finding and local-avoidance.
One problem is when multiple units being ordered to the exact same position, they can never reach the position due local-avoidance and collision.
Only this will make the units scratch each other, this will also cause the unit not able to STOP, as the unit might be still far from the target position. And whether stopped or not is important for battle (unit can only attack when stopped).
I studied how SC2 handles this, it appears that the units will stop after a few seconds of scratching.
PS, I have used group formation to avoid the situation, but it can not be avoided, when the group are ordered to goto some impossible position, and they would cluster at the edge of the valid navmesh.