use strict;
use warnings;

my @x = ( ['aaaaa', 'bbbbb', 'ccccc', 'ddddd',],
          ['eeeee', 'fffff', 'ggggg', 'hhhhh',],
          ['iiiii', 'jjjjj', 'kkkkk', 'lllll',], );

my $tolerance = 1;

STEVE:
for my $outer ( 1 .. 5 )
{
  TONY:
    for my $some_x ( @x )
    {
        my $fail = 0;
      BRUCE:
        for my $just_this ( @{$some_x} )
        {
            my $c = "..."; # ... get string for pattern matching here.
            $fail++ if $c =~ /\Q$just_this/;
            next STEVE if $fail > $tolerance;
        }
    }
}