Dean is a very smart man.
Static stretching as outlined in his article doesn't really "fix" anything. Mobility work along with soft tissue work of key areas is what fixes you up.
That said Jim Wendler says something along the lines of "if stretching makes you feel/perform better then stretch".
To open your hips you likely need mobility/soft tissue work. If stretching personally helps you then do it after a training session and not before if you can help it.
In short- do what ever works for you.