Maybe, as long as the sentence isn't a quotation from anything online or exceeds 50 characters or so. Dictionary attacks use entire phrases now, but they still don't go beyond a character limit that's fairly low compared to entire sentences.
Some additional password fuzzing techniques to consider.
- Putting nums or special characters between syllables in words, not just between the words.
- Using multiple specials/nums between each word.
- Strange uses of spaces and punctuation.
- There are 2 additional ways to encode alpha characters as numbers besides 1337-speak. Use alternate means.
- use puns or homophones to make your phrase less likely to match a dictionary.
As far as the OP, there are some things that your company can do to improve security without completely abandoning the passwords. They may find some of these more palatable:
- Instead of sending new password direct to user, send an access code to the user's manager. User has to request the access code from the manager, then use the code to login to the site that gives them their temporary password. This has the additional advantage of bringing to manager's attention which employees are particularly bad at remembering their passwords, and who probably need more attention to assure they don't have any sticky note reminders on their desktop.
- Rather than use full 2-factor authentication, just enable a standard password locker software to install on each employee's computer and give them a flash drive to host their password file. This is a lot cheaper than buying customized smart cards or key dongles, and is significantly more secure than what you have now, especially if they use the random PW generators that most lockers make available.