But I don't think it's that long a url.
For perlcheat, it doesn't matter how long a URL feels, or what you think is appropriate. It's about number of characters and what will fit, and what will not.
I also think the reason it's perldoc.perl.org and not doc.perl.org, is that the previous url was perldoc.perldrunks.org and nothing to do with Google ranking. I may be wrong however.
I can't find the specific message, but I was told that "perldoc" had to be in the url, as a whole, to get a greater chance of getting to perldoc.perl.org if someone googles for "perldoc perlop".