The generated ppd file is coming from Perl tools (ExtUtils::MakeMaker or Module::Build); these make a guess about the package the prerequisites are found in (based on the specified module name), but sometimes the guess is wrong (eg, Win32::OLE is in the libwin32 package, not a Win32-OLE package).

This explains a lot. Looks like the same issue that happens with RPM packages on Linux: packagers choose a package name that best fits the requirements.

This would be easier to solve if the PPM is capable to search the available Perl modules inside a PPD package. I would be able, at least, to maintain the dependency list in my PPD file, even if I have to do it manually. I tested all options against Hash-Util, without any results.