That being said, our job titles aren't exactly hard and fast representations of what we do day-to-day.
Check out the subtitles here for examples: http://automattic.com/about/
Don't get me wrong, I think you can give yourselves any title you want, but when listing job postings you're just creating barriers by using non-descriptive, non-standard titles. Your potential applicants have to check the job description for "Account Engineer" to see if this is something they would be interested in (for most it won't be), if someone was actually looking for a client/account director role they might not notice this one because of the "engineer" part, and if someone was looking for a blended support/coding role they might miss "Happiness Engineer" while scrolling down the page.
If someone wants an account director job at Automattic and never makes their way the Account Engineer link, that's okay. If someone is a bit intrigued by our non-standard titles and looks a bit closer at them because they stand out, that's cool, too.
Anything that isn't normal might confuse people. The goal of our jobs page isn't to confuse the fewest people possible.