It's complicated, I agree. But it's pretty easy to create a PHP script that lets you put in the time limit, goal completion time etc and then calculates the scores, if you want me to I could even make it.
I don't have much problems with counting it as a "small" event, but my main concern is that you can only get 5 points with this kind of events, while Assault games usually take a lot of time (so the points aren't really wort the effort).