According to the following dictionary entry, ‘vocabulary’ can be accountable and unaccountable. So when to use it as accountable or unaccountable?
1 [C] all the words known and used by a particular person:
a wide/limited vocabulary
By the age of two a child will have a vocabulary of about two hundred words.
2 [C or U] all the words which exist in a particular language or subject:
Every week our French teacher gives us a list of vocabulary (= words) to learn.
Computing, like any subject, has its own vocabulary.
I cannot, offhand, think of an occasion when I might use the word vocabularies.
(I think you meant to say count and noncount.)