The only problem with it is that you're going to be carrying the Sort key after you no longer need it.

ST to the rescue!

sub computeSortKey {
   my $aref=shift;
   my $sort;
   my $M = 100;        
   for (@{$aref}) {
            $sort += $M * $_;
            $M = $M / 100;        
   }

   return $sort;
}

#Schwartzian Transform
@Tree = map  {$_->[0]}
        sort {$a->[1] <=> $b->[1]}
        map  {[ $_, computeSortKey($_->{Path})]}
        @Tree;
[download]

The advantages of doing it this way are that
1) it's a well known idiom, so a lot of perl programmers will grok right away what you're trying to do, and
2) you don't keep the sort key around after you no longer need it, so it keeps @Tree relatively clean.
--
Mike