Do you really need the array? A bag-of-word is independent of word order, but with the keys keyword you'll have access to all your words.

sub toBagOfWords {
  my %bag;
  $bag{$_}++ for split /\s+/, shift;
  %bag;
}

my %hash = toBagOfWords "I see their knavery this is to make an ass of
+ me";
my @words = keys %hash; # if you still need the list of word, in a "ra
+ndom" order
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