Why not? there is nothing wrong in disabling them, at least if you know why they are happening:

@sorted = map{ $_->[0]} sort{
               no warnings 'numeric';
               $a->[2] <=> $b->[2]
          } map{[$_, split/sequence/]} @unsorted;
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However, for this particular case and as already stated in other monks answers, it is easier to extract just the number.

Besides that, if you are concerned about the sort performance, you should try Sort::Key and Sort::Key::Radix:

use Sort::Key::Radix 'ukeysort';
my @sorted = ukeysort { /(\d+)/; $1 } @unsorted;
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