Fixed. Scroll three down  -- >  http://theoatmeal.com/comics/misspelling   |  It's a nice read.
As for catapults. I really do not see the need, and I do not even know if they were used back then.
 
 Actually it would be 
they're Joe you should go back and read your own link.
As for the OP, I don't see much need for them but they could be fun. 
I say +1 as long as the dev time doesn't interfere with more pressing projects. 
* edit to save Skuzzy the trouble