[professorTuring]

lower, upper and numbers = 62 options | wordlist = 10 000 options:

    62^12     = 1e21
    10 000^5  = 1e20

The problem is you not using a word generator and instead relying in your invention, most of the people will use top 5000 words (5000^5 = 1e18), imagine you can even lock one of the words (a color maybe?).

So this way of thinking might be good if you know what you are doing and use uppers and lowers and symbols, if not, it is actually a bad advice.