If a coach is allowing kids to evaluate themselves based only on the time in a meet, that program is in trouble in a way that discussions on a message board are never going to solve.
Telling someone you think their course is short is akin to calling their significant other ugly. They most likely aren't going to see things your way, and you are only going to anger them. You're not going to convince them.
There is no agreed method for measuring a cross country course at any level. If you tried to apply the methods used for measuring a road course, most people don't have the necessary equipment nor the training to use it. The measuring wheels you pick up at Home Depot aren't intend to be used measure things 5000 meters long. Have 10 coaches bring their 10 wheels to a course and have them measure it. You will get 10 different measurements, some remarkably different. Have 10 coaches use the same wheel on a straight course over grass and you will get 10 different measurements. Add in some lumps, hills, roots, turns, etc. and the differences only increase
Don't even get started with using GPS on a course with significant turns, hills, trees, etc.
Are times useless? Not at all, but they aren't much good without some sort of basis for comparision.
The best possible scenario is comparing races run on the same course on the same day with similar conditions. Note that Boardman this weekend wouldn't qualify for that since the conditions in the morning were much different than the conditions in the evening. If you had a day with relatively stable temps and course conditions, it would be reasonable to compare runners times in the JV, Varsity, and Open races.
What about week-to-week? I do this on a regular basis. If you have larger meets with a number of teams who run them both, you can determine the typical difference (change in median times) and get a rough idea of how different the courses ran and then evaluate how your athletes did relative to the typical difference. If conditions are vastly different, I usually restrict the comparision to the top athletes who are less affected by things mentally.
If you are fortunate enough to have a mentally tough senior, then you can use them as a reference and look at the deficit of the other runners to that reference. That falls apart of you don't have such a person, or they get sick, injured, etc.
There is no reason to call a course short since we don't have a way of accurately measuring courses anyway. I think it's fair to say race A ran ~## seconds faster than course B after you look at the differences in the times for the athletes who ran both races. You're not attributing that difference to the length of the course, the conditions of the course, the typical training modalities used in the prior week, etc. You're simply stating an observation.
You're better off trying to get athletes to accurately assess how they did without knowing their time. What's going on inside their head before and during the race is the important stuff. The time is a symptom that can be misleading. If there are common themes within the team that need to be addressed, then you can do that verbally and help them with ensuing workout designs.
Chasing after times means that your athletes are going to miss the fun of racing in the mud, on hills, etc. They will be disappointed and difficult to motivate for any meet that isn't flat, fast, and in awesome weather conditions. It destroys the best part of the sport in my opinion.