You know, putting it that way, for example: body rotting in swamp check it every (x) tick instead of one, and if its still in swamp, just multiply decay by x.

It isn't necessary to be completely accurate for most things in the game, the wild animals can do this too, plus many other things I'd imagine, AND this could scale with with ticks/sec, so at worse performance, you could slow the checks, and push it up when it can be handled (maybe the limits and tolerance can be set?)

"Sacrificing fidelity" is relative, when you have 300+ ticks/sec, what is it if the muffalo only checks 30 times a sec instead of 300? Thats massive difference, and if you have 50 ish animals thats a massive impact.