Completely differently, you could use do to insert the code into the current namespace.

foo.pl:

our $var_a = 1;
our $var_b = 2;
1;
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bar.pl:

our $var_a = 3;
our $var_b = 4;
1;
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main.pl:

#!/usr/bin/perl

use strict;
use warnings;

do $ARGV[0].'.pl' or die;

our $var_a;
our $var_b;
print("$var_a, $var_b\n");
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Output:

>perl 558119.pl foo
1, 2

>perl 558119.pl bar
3, 4
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