What I'm trying to do is:
1. recurse through 5 different directory structures. Each directory structure contains identically named files.

'Recurse' seems to imply that your directory structures might have subdirectories that you wish to recurse into.

If this is the case, or even if not, a solution based on File::Find might fit your needs. For example:

#!perl -w

use strict;
use File::Find;

my $prefixDir = "$ENV{HOME}/sa/current";
my @clusterDirs= ("$prefixDir/cluster1", "$prefixDir/cluster2", "$pref
+ixDir/cluster3", "$prefixDir/cluster4", "$prefixDir/cluster5");

for my $dir ( @clusterDirs ) {
    print "$dir\n";
    find( sub {
        return unless -T;
        printf "file: $_: %d\n", -s;                # file name only
#       printf "file: $File::Find::name: %d\n", -s; # full path
    }, $dir);
}
[download]

Cheers, Rudif