My experience with the two Gravel races we did this fall here in Colorado south of Denver, in the Greenland area was; First, an endurance approach, in a road race you can hide in a peloton, the dirt makes you work. Two, have a bike that works with you and your level as a rider. If you are a strong rider you can over come equipment that might not be ideal for you. I rode a road bike in both races, finished in top third both times, and lost time in the single track, and in the deep sand, my level as a rider would have benefited from better setup. I love it when i see these guys go out with single speed bikes and kick A_ _ , they are super strong.
Just my thoughts, too i am working on a better bike!