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;