I really think this idea that duplication of things in contrib is bad, is bad (or just a red herring).
For ports of big applications (python, say), the amount of work involved is going to self-limit the number of ports right up front. And the ones that do make it will self-select based on the quality of the port. As for the smaller things, I would prefer to see ten different bits of code that achieve the same end vs. just one. Diversity is good, and a broader selection of code gives a bigger field to mine for ideas and concepts. --lyndon