Nitpicking alert:

You seem to parse packages. But modules are files.

There is a convention to have the whole module included inside an equally named package, but with no guaranty it's respected.

I'm not sure, but it might be possible to require a file which doesn't match your regex for identifiers.

update

more nitpicking:

use utf8 allows extended identifiers, and my test allows umlauts in use MODULE and package NAME

use strict;
use warnings;
use lib ".";
use utf8;

use äöü;
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# FILE äöü.pm
use utf8;
package äöü;


use strict;
use warnings;
use Data::Dump qw/pp dd/;


warn "äöü included";

1;
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output

C:/Strawberry/perl/bin\perl.exe -w d:/tmp/pm/mod_uni.pl 
äöü included at äöü.pm line 10.

Compilation finished at Tue Feb  8 02:46:11
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