I have seen the self cocking (loud and slow) and the repeating versions(quick and easy, but low power). Also,did you know crossbows can be set like deadfalls to watch a particular point of trail? (not legal here), but a crossbow can be strapped to a tree, with three trigger strings. one at the point of impact, and one each uptrail and down trail at shoulder level. men on trail discharge early, deer or large animal discharge at point of impact. But under a survival situation, it could make the difference between eating and not eating., especially if you happen to be weak or wounded. It is a useful tool, but it is still a bow tied to a stick, with a different kind of release.
The only real difference between a good tracker and a bad tracker is observation. All the same data is present for both. The rest is understanding what you are seeing.