Northern slopes of Wildcat Hill - Part 2

Continuing from here, this part seemed a bit older, certainly a bit different from the rest of the hill. Starting with a low pile, larger than what I saw earlier:Above it, a degenerate pile and an outcrop with traces of structure on it:[That first pile shown is down hill from here at the edge of the wet.]

The outcrop looked down over a shallow semi-circular dell with wetland at the bottom. At the edge of the wetland: a pair of larger piles, broken down.And guess what? One of them had a hollow:The hollow, or "dimple" is not very visible in the picture, just left of center on the near pile.
I would like to understand some connection between these two things: marker piles and piles with hollows. These are things I see, and see frequently. I do not see them together but I see them, so to speak, in close proximity. I have talked about "ski jump" and the thought that they might for a "missing link" (see here) between these different kinds of sites. Here at Wildcat Hill, the relationship is more one of direct proximity: 50 yards away are marker pile sites in more than one direction. It could be the same culture doing different things but I get a sense of these piles with hollows being older and more broken down. Time will tell if there is any reality to these observations.