Note: I managed to screw up again by posting this in the wrong place. Two gaffes in a day. I hope the gods will forgive me.

If you seek a one-liner answer, I don't know what it is, but if you just want to get the job done, then simply transpose the matrix, apply the earlier solution (for ordering according to the n-th row elements), and then transpose back. I.e., for the general case of a non-square matrix,

sub transpose {
  map {
    my $j = $_;
    [ map $_[$_][$j], 0..$#_ ]
  } 0..$#{$_[0]};
}

my @array = ([8, 9, 10], [6, 5, 4], [7, 8, 9]);

my @sorted =
  transpose
  sort { $a->[1] <=> $b->[1] }
  transpose @array;

1; # target for c in DB
__END__
  DB<1> x @sorted
0  ARRAY(0x8359764)
   0  10
   1  9
   2  8
1  ARRAY(0x84bdcb0)
   0  4
   1  5
   2  6
2  ARRAY(0x84bdc8c)
   0  9
   1  8
   2  7
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