Likely the best solution will be a give-up timer that progressively increases the acceptable target distance in case the unit can't get closer.
Since this is meant to prevent vibration on stacking right next to the target, the maximum giveup distance could be limited, so that the units that aren't really close to their target would never give up.
Likely the best solution will be a give-up timer that progressively increases the acceptable target distance in case the unit can't get closer.
Since this is meant to prevent vibration on stacking right next to the target, the maximum giveup distance could be limited, so that the units that aren't really close to their target would never give up.