An event also needs some direction, and the potential for different outcomes. For example, we need the ability to push back an invading force to it's original position, and mount a counter-attack that would end the invasion. If a defending force outnumbers the attackers, a counter-attack should *always* be an option. A fight isn't a fight without that option.
Also from what I saw last time, the forces do not approach in a structured fashion, but just keep coming in a steady stream as they are killed. Even a semi-intelligent force would change their tactics to suit the current battle situation. Attacking forces have objectives, and attacking forces have a reason for attacking. And that reason isn't to be killed at the front lines due to crap tactics.
I know people are bored, but surely fighting wave after wave of the same kitin until they stop, every time, isn't really relieving that boredom?
Hardly any of the stuff above is present, so why will these invasions actually be interesting? Sure, we haven't done it for a while now. Well, if I leave washing the dishes for ages, sure enough, when I do it again it's no more interesting than it was before.
