If your intent is to motivate the troops to do better, don't have crazy tight time limits.
Your time limits need to be consistent. Are you going to add time if the officer is using a holster with a higher level of retention, or if they are drawing from concealment or encumbered with rain or cold weather gear?
If you make the time limits too tight the shooters of average ability might just say "I can never go that fast" and check out, OR rush too much and forget to look at the sights and jerk on the trigger. So then maybe they train themselves right into a bad habit that you then have to work to overcome.
Using a drill that is in common use across the country might be a good idea. The 5x5 drill now used as an alternate classifier by IDPA is a nice little course.