mutant creature in water
I've noticed that if the river is deep, often some mutants can run under the water and attack you at higher range than they are.
This can become a problem if you for example swim up on a shadow bear without being aware of it cuz your looking forward across the water plane going forward, you won't see down into the water as easily this way so creatures can easily hide under it.
This also means that if you kill them while in this deep water, they will be too far away for you to harvest their bodies, since the body will be at the bottom of the river, out of your harvest range.
Animals that seem to be problematic:
mutant bears
mutant deer
mutant coyote (hunchback seems less effected than the canis armadillis that seems to like hiding in the water more)
From what I can see all other mutant's and creatures don't share this issue.
This could be a simple issue of editing those creatures so they swim in less water than they are currently set for, this would force them to swim instead of run along the bottom of the river, and the body would be ontop of the water instead of bottom of the river.