Seems like if you get the size of the array produced by the reverse sort, you ought to be able to come up with some sort of incrementor:

my $incrementor = int((scalar(@my_array) / 2));
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Then you could step through the array printing the elements at indices $i and $i + $incrementor on a line:

  for (my $i=0;$i<=$incrementor+1;$i++) {
    print $my_array[$i], "\t";
    print $my_array[$i+$incrementor] if defined($my_array[$i+$incremen
+tor]);
    print "\n";
  }
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Code is untested and without warranty.