Count the number of targets (paper or otherwise), par time by count of targets. That's the maximum amount of time you can spend on each target, not including movement.
OR, count arrays and the amount of time you need to get to the next array. Subtract dwell time (time to next target array) from par time, then divide by array count. This is the maximum amount of time you can spend at each array.
Now decide which array or which receives more attention if you can't run the the COF in par time.