Moreover, the discrepancies between the tokenized input data and the third party data (when tokenized using a generic tokenizer) might prevent matching correctly VMWEs which contain words tokenized in a different way.
vMWEs frequently include function words which are susceptible to tokenization errors, like "c'est" (it is) in French: if the tokenizer does not properly recognize the apostrophe as part of the first token "c' ", 17 expressions which contain "c'est" cannot be matched.