If you're using a password manager, shouldn't you just have it generate a random strong password you don't expect to remember? If you're remembering it, it's really best to not use noise, just plain correctly spelled lower case words. Adding an additional word adds both more security and is easier to remember than adding an ampersand somewhere in your password
What it generates you have control of. So you can say "I want uppercase, lowercase, numbers, characters, of length X". So the guidelines are still relevant.
The only thing you should remember is the password into your password manager, and if you want to add more words, by all means; I just find it quicker to type, no harder to remember, while making a dictionary attack unfeasible, by adding a character or two to the passphrase. I.e., "correct!horsebattery,staple" (though I agree that at four words you're fine anyway; I'm just saying that with a little noise thrown in I can type two or three words, plus a couple standalone, easy to remember characters for the same level of complexity)
