Alright, let's talk about GPS and cross country courses because a lot of NIRCA teams really don't seem to understand how this works...on an accurate cross country course, your GPS watch is very rarely going to read 4.97 miles. That's actually more likely to happen on a short course. Why? The two important things to understand with how GPS works in running watches are sampling rate and "smoothing". The running watch industry has a standard sampling rate of 1s (your position is recorded every second). When you're running on a straight line, this matters little. On turns, this would lead to your watch recording that you ran less distance than you actually ran, as it will record a turn as a tangent of all the locations it recorded, rather than the arc that you actually ran. However, this is accounted for in running watches by "smoothing" the data points. When your watch records you running a turn, it calculates an arc between your data points instead of those tangents (if you want to dig into this more, most software uses a Kalman filter for this calculation). The point here is that "smoothing" actually tends to measure MORE distance on turns than you actually ran, rather than LESS as the raw data would provide. That's why when you have your GPS on during a track workout, your auto-lap will typically record a mile as you enter the homestretch, but still have another 50-70 meters to finish the mile. The smoothing required due to the limited sampling rate overestimates the distance ran. It's not that every track in the world was built incorrectly. To summarize this part: your software smooths your data which adds distance.
Next is human error. Nobody is running a perfect 8000m or 6000m during their XC races on a correct course. Courses are measured manually using the perfect tangents possible to run the shortest distance. There's also differences between courses marked with one line versus boundary lines on both sides. Look into course marking in more detail if you want. The point is that in a packed race, nobody is running perfect tangents. On looped courses with tight turns, trying to run perfect turns is going to hurt your momentum more anyway, so it's not even always best to run the course "perfectly". Summarizing this part: you're not running the course perfectly which adds distance.
Lastly, GPS is not that accurate. GPS was not invented for tracking runners. It was not invented to be accurate down to the inch. Here's a great article on GPS accuracy with watches and footpods (footpods are more accurate):
https://fellrnr.com/wiki/GPS_Accuracy
. Even with perfect signal on an open field, it's just not that accurate. The Garmin 235 is one of the most popular watches out there right now, and that has a 5% margin of error on accuracy with a perfect signal. That's 400m over the course of an 8k and 300m over the course of a 6k - that's a ton. Even if you ignore the first two sources of error, you could expect your GPS watch to say up to 5.22 miles on an accurate 8k course (that was measured manually, NOT with GPS). GPS accuracy tends to get the distance short with a poor signal due to obstacles (trail running for example), but long without obstructions nearby (tracks or open cross country courses). Part of it, again, is due to sampling rate and smoothing, but part of it is due to the fact that the data points of your location are not perfect. Summarizing this part: your watch doesn't know EXACTLY where you are which adds distance (or can reduce distance).
Consequently, looking at the strava data from some of the regionals makes it pretty clear that Mid-Atlantic was almost certainly a short course. Great Lakes might have been a little long, but there's no way to know that from the GPS data. Measurements of 5.1 miles are very typical (and expected) from a multi-loop cross country course that was measured correctly.
I get why we like ignoring these things. It's fun to think we're [sub-25, sub-26, sub-27, etc...] or [sub-21, sub-22, sub-23, etc...] runners. It's fun to compare PR and run our "best" races. But when GPS isn't accurate, not all courses are accurate, terrain differs, weather differs, that doesn't matter. Cross country is not about times or PRs. I know they're fun, but it's just not reasonable. Look at the NIRCA top team averages at an XC Nationals event. They're all from 2011 at McAlpine Creek Park, on a course that was definitely short. Does that mean no team has been better since then? Of course not. It's not about the times. The teams and individuals that run to pace for a certain time on Saturday are going to lose to the teams that run to race for a certain place. It's cross country, that's just how it is.