When I do 'man List::Util', I hit a slash, type the name of the function I want the manual of, hit return, and it appears. When I do 'man POSIX', I hit a slash, type the name of the function I want the manual of, hit return, and it appears.
There's no difference if you know exactly what you're looking for.
Ovid $ man POSIX | wc -l
Ovid $ man List::Util | wc -l
You're assuming the person knows what they're looking for. If they don't and they have only a vague notion that the package in question supplies what they need, it can be a long slog indeed to find the answer. Searching for poorly named functions is harder. Verifying the behavior of complicated functions is harder. I'm not saying shorter/simpler is better, but it's often easier to work with.