Let's be perfectly clear, marketing automation is not a strategy and it is not a tactic. It's a tool. Saying marketing automation is a tactic is like saying your business strategy is to achieve double digit growth. For either statement to matter, you must have some thought and action behind the desire.
Regardless of what the MA vendors say, these marketing systems are highly complex. They are akin to powerful image processing programs like Adobe Photoshop or complex accounting programs like Peachtree. These programs require hundreds of hours of use and training before a user is able to be proficient.