It's about time. Good for you.
You are completely correct that the best way to run XC is with an even pace...or more accurately...an even effort. Most people do go nuts...especially high schoolers and it creates enormous opportunity for somebody who can stay cool and stick to their guns.
This assumes, of course, there is nothing particular about the course...like it goes down to a narrow path where you can't pass 1/4 mile into the race.
I firmly believe the real damage is done in the first 300-400m. This is where everyone really loses their marbles. They've settled down well before the mile...mostly because reality has set in.
Running the first 400m in 70secs...let's say...is going to handicap a 16:30 5K runner quite a bit...yet so many do it. I'll bet they lose 15-20secs on their overall time.
I coached a runner who literally stole a 12th place finish in the states...simply through good pacing. He was about a 17:10 runner. The first mile was all uphill...some of it kind of steep. We talked a lot about even EFFORT and practiced it quite a bit. I told him a 6:05 first mile would be just fine. He executed it perfectly...hitting the mile in exactly 6:05. He was in 40-50th place. As the course descended he blew through the field and ended up running 17:10 on the tough course.
He beat runners he had no business beating. But the opening hill made the good pacing even more important.
People talk a lot about tactics. But I still feel the best tactic is to get from the start to the finish in the shortest possible time. Hence...good pacing is the way to go...for most anyway.