Depending on the task at hand, either approach may or may not work well. I know that there are plenty of successful Perl projects maintained by experienced small teams with 50,000-150,000 lines of code. (Should you count the CPAN modules that also got installed in lines of code?) Using the estimate that Perl code is 6x as dense as C, that's similar to 300,000 to 900,000 line C projects, only done in less time by fewer people. (OK, it runs more slowly and it takes more memory.) Conversely if something would take more than a million lines of C, Perl is likely not the right language to choose.
This leave me wondering, does this imply if something takes more than
150,000 lines of code in Perl, then perl is likely not the right choice.
If yes why?
And does this imply if something is taking more than 900,000 lines of C, I
should start looking for a different language, but not Perl.
I personally think, the answer to the lines of code can be a lot more
structured, for example, if you have more then N lines of code
use namespace, or package (Tcl vocabulary)
or consider using an object system
If c doesn't have those, then c fails
If perl does, then perl will succeed.
Of course I can imagine, other language features can affect the choice
when faced with the problem that too much code is being written
But I believe this porblem is very structured, and can be answered
very specifically, and languages performance and ability to face this
problem can be determined more precisely.
No need for estimates here, we don't have to guess.