I can’t tell you how many people I’ve heard bemoan the limitations of draconian style and design guides for their corporate web site. It is a very common complaint and always happens to a certain extent. However, when the complaints are endemic it’s usually because the department that manages the site has determined their job is creating compliance rather than results.
The best web teams are those that focus on generating results above all else. Guides and standards can be very useful tools and I’ve helped to generate a bunch of them. However, they are a means to an end. Don’t let your guidelines become straight jackets that limit your ability to achieve fantastic results online.