Better in terms of getting the word in fewer guesses, or in terms of not taking so damn long?
Not knowing much about the algorithm, it's hard to say. It may depend on how the AI is searching the dictionary.
It may also depend on what kinds of words are in the dictionary. For example, if you've got a lot of words that are anagrams of each other or lots of words that are very similar, then that's going to impact performance. One factor to look at might be the average number of words that have 4 (or maybe even 3) letters in common with a given word. A person with a limited vocabulary can make a correct guess fairly quickly once they know 4 out of 5 letters, but an AI that has access to the whole dictionary has way more possibilities to consider than the person does.