As the (very remiss) maintainer of XML::SAX, I'm also mystified by the reports you're seeing. If XML::SAX was properly installed, then there would be at least one parser module that meets the requirements you've specified.
One way to get more information would be to have one of your early test files emit more diagnostic information via the Test::More 'diag()' function. For example, it would be interesting to know what the default parser is on those servers (the class of the value returned when XML::SAX::ParserFactory->new is called with no extra requirements). It would also help to know what is actually in the ParserDetails.ini file but the exact pathname to the file will be different on each host and working it out requires replicating the %INC gymnastics from XML::SAX.pm