Preta actually can absorb shadow clones, if pein can siphon the chakra out of a normal body Naruto what makes you think preta as a whole cannot absorb a simple shadow clone? The preta actually isn't a hyperbole, a technique can say one thing but it's dependent on the user if they can handle it, for example if pein used preta (which he did) on a sage mode user he can absorb it but he can't properly handle it would turn him into a frog it if on a DSM user a snake. But if madara used preta and absorbed then he has a better suited body to handle that chakra, pereta path itself, stems from Kaguya, it's havily dependent on the the combination of the user's body,, preta can absorb it but can the user handle it is another scenario.
A Hyberbole would be Temari's winds, blowing away the universe, it just means her winds are very strong but people take this too literal. Some jutsu aren't hyperbole's when described, they are actually truth.