the language is so fantastically huge, no two programmers even appear to be writing in the same language

He's absolutely right that divergence in programming dialect between programmers is one of the biggest problems in maintaining large bodies of code. However, I don't agree that the size of the language has anything to do with the problem. C code written by two different people can be just as radically different as Perl code, and C is small language.

The only way to guarantee that Perl code on a large project is "read-write" and not "write-only" is the same as with any other language - coding standards and code reviews to make sure they're being applied. Nothing else will ensure that a group of programmers is coding in the same dialect.

-sam