It's usually easier to use $labels[0] and $hash{$labels[0]} instead of maintaining the same order in the content array. I think that's what Laurent is getting at. But if you really want to have a bunch of parallel arrays, here's the pattern for sorting them:

my @order = sort { $labels[$a] cmp $labels[$b] } 0 .. $#labels;
@labels = @labels[@order];
@content = @content[@order];
@more_content = @more_content[@order];
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