"Is there a pacing strategy?"
Yes, like just about any other race, even pace works best.
However, between hills, footing and field size vs course width that is hard to do.
If you are really in 17 flat 5k XC shape, you should be able to run 28:30 if you were paced by someone who ran exactly even pace and all you had to do was stay with them.
Since that isn't going to happen, and the go out fast and hang on already didn't work, try to run as fast as you can without pain for 3 miles. That should be about 18:00. From 3 miles to the end, pick up the pace and hurt. It will hurt almost immediately if you did the first 3 miles correctly. You will run mile 4 faster than the first 3, maybe 5:45. Then run the last fraction as hard as you can.
This method should get you under 30 no matter what. If you run under 6 for the first mile, you will just break 30. If you can run over 6 and then run near 6 for the next 2, then the painful mile 4 and pushing the horrible fraction will get you down to 29:30.
Remember, 8k times vary even more than 5k so hang in there, you will learn the race soon enough.