Not stupid at all! There's a long tradition of figuring out what it means (just google "Blood Meridian epilogue"), but the short answer is that McCarthy was probably playing around with ideas, having a bit of fun, waxing poetic. But there's some elements in the passage about determinism, causality, exploitation, the man with the instrument being a "pioneer" of the American West, the holes being railroad tracks, or fence posts, or mine stake poles (referencing the imminent gold rush), etc.
Like like with all poetry, it's a joy to think about and dissect.
Like like with all poetry, it's a joy to think about and dissect.