I think if the snails could devour a cleaner or coral banded shrimp the peps should be quick work as well.
I have never owned a coral banded(I know they are considered one of the most aggressive, thats why I never purchased one)

or harlequin but have kept fire shrimp, cleaner shrimp and peppermint shrimp with nassarius with no problems. Although mine werent the huge tonga ones, just the caribbean ones. They are fast little snails though. Plus I have heard of weird stories like a coral banded eating fish etc. so who knows with nature.