Since I am working hard on iteration 4, which is something like a milestone, just brief info on iteration 3:
Main theme of 3rd iteration was implementation of formation, movement in formations and formation to formation movement. It was much harder to implement than I expected, since I had to do some changes to my engine/framework. In the end it took 16,77 hours to finish it. 16,30 was spent on formation. But I was kinda cheating, in the end I discarded all other planned activities in favor of formations.
I kinda wanted to share the design I came up with, but it's just probably all wrong and can be done better :) There are probably better sources.