my %words;
++$words{$_} for /\w+/g;

for (
   [qw( Fred Flinstone )],
   [qw( Barney Rubble  )],
   [qw( Joe Rockhead   )],
) {
   next if @$_ != grep $words{$_}, @$_;
   print("matched @$_\n");
}

##</code><code>##

my %next_words;
$next_words{$1} = $2;
   while /(\w+)\s+(?=\w+)/g;

for (
   [qw( Fred Flinstone )],
   [qw( Barney Rubble  )],
   [qw( Joe Rockhead   )],
) {
   next if @$_ != grep defined($next_words{$_}), @$_;
   print(join(' ', map "$_ $next_words{$_}", @$_), "\n");
}