For a moment keep 'OO' aside, Imagine what would happen if in a single program three different 'if' synonyms, 'switch' synonyms etc

The project manager would fire the programmer. But that's still beside the point, because that's not what happens in those syntax experiments.

You keep repeating the same thing, so I'll try one last time to explain the difference to you:

'if' is a simple, well-understood concept that exists already in the Perl programming language, is well integrated with all other features in the programming language, and is very short. There's not much you can add to an if-statement to enhance its value (at least I haven't seen any experiment that demonstrates added value).

Most syntax experiments (signatures, OO, overloading, grammars) explore complex concepts that are not yet present in the language in they way envisioned by the authors, and often try to provide concise ways to express things that are already possible, though not as easy or convenient.

(If you're not convinced that those things are indeed complex, and need thorough exploring before they can be done right, I suggest you take a look at the excellent talk "Perl 6 Signatures The Full Story" by Jonathan Worthington: video, slides)

SO I can't understand why you keep comparing things that are so wildly different that they can't be compared in a meaningful way.

However a proper guide/policy is needed as to indicate what is saner/safer to use

I agree that we need a better way to collect the knowledge of the perl community about which module to use for what task, and to make that knowledge available to the casual perl programmer who doesn't actively participate in the community discussions.