I followed a half marathon training plan and found it very useful and helpful. As someone who is not an expert in running - I found those plans amazingly useful.
However all the workouts are based on heart rate zones, like run in Z2, then Z4, etc, which is very individual.
I managed to run half marathon eventually. Now my goal is to improve my speed and complete my next half marathon for example in one hour and 35-45 minutes.
However none of the proposed Training Plans takes the target time as a goal. I think it will be great addition instead of proposing Level 1, 2 or 3, offer more training plans that has a time as a target goal.
Gil