Yes that darn *first* makes it seem like you are right. 

But in my ignorance I'm going to see if I can come up with 12 words the way I was doing it. Might get an answer and be wrong, but I think I can do it fairly quickly. 

Scoresby

There are 10 four letter words and 2 three letter words

That is ambiguous. I do however believe that what is meant is that those words are four letters long only after truncation, from the sentence that follows:

 four, and three, letters of each word are what I have provided.

bitcoin

100k sat prize for solving bitcoin seed phrase puzzle

> There are 10 four letter words and 2 three letter words

That is ambiguous. I do however believe that what is meant is that those words are four letters long only after truncation, from the sentence that follows:

> All of the **_first_** four, and three, letters of each word are what I have provided.

(emphasis mine)