[naravara]

The comment you're addressing seems like an ecosystem equivalent to what economists call the "lump of labor fallacy." https://en.wikipedia.org/wiki/Lump_of_labour_fallacy

"Lump of biomass" fallacy might be a name for it.

As for the carrion bit, apparently when they returned wolves to Yellowstone, it wasn't just the invertebrates and raptors. Even the bears started putting on weight because the wolves were surplus hunters and would leave a lot of meat lying around for the bears to scavenge before winter.