Strength testing password used to create user account
Seems like CiviCRM might not be calling the right functions within Drupal (which trigger hook invocation that modules like password_strength or password_policy implement.

Would be good if we can adapt Civi's code to do the right thing. The user/password creation for drupal is isolated to the file:

CRM/Utils/System/Drupal.php

Check the functions createUser and checkUserNameEmailExists