It is easy to have 1 year of experience 10 times, and think that you have 10 years of experience.

I have no idea whether this is true for you. But it has been true for a number of people that I've worked with.

Back to the topic at hand, Perl is a very different language than C or C++. Sure, it is easy to write C in Perl. Just like you can write Fortran in C. If your C coding habits are clean, the result won't be that bad. But it won't be anything close to idiomatic Perl. Your answer a couple of posts ago demonstrates exactly how non-idiomatic. Which is why I'd prefer to see more Perl experience in a potential mentor or lead programmer on a Perl project. (And I'd like to see experience of the sort that leads to "5 years of experience" rather than "1 year of experience repeated 5 times".)

On your comments about ability to learn being more important than existing expertise with a language, that can be very true. I've been in the position of hiring people who I was supposed to teach Perl to, and have some idea how to do it. However it is somewhat hit or miss, you can't know in advance whether a given person will readily adapt to new ways of thinking or not. And there is always a learning curve.

So if I'm hiring to lead, I want to pick someone who I think can grow, and who also has the skillset I want. I want both.