I'm in high school and I try my best to even-pace my Cross Country races. I'm not fast enough to go out with the leaders, even at a dual meet, but I am able to be confident with my strategy because I can feel the pace I'm going out at, while not "hard" in the first 800m, is fast enough so that all I have to do is hold it to have a great race. Also, I have been successful using this strategy in both Track and Cross Country. You're right that the average high schooler runs huge positive splits but if you averaged my best races, you would get an even-split or even a slight negative-split.
So while I encourage you to be confident about this strategy, I must admit that it can take more than one race to execute. This was the first year I really focused on executing even-split races and it took a few tries but by the second-half of the season, I was confident going into every race that my strategy would not hold me back.