The type and number of units you start with is variable. In one game I was given two colony units, in others only one. Can anyone tell me how this is decided?
As far as I can tell on the top two difficulty levels you always get 2 colony pods. On lower difficulty levels you seem to randomly start with 1 or 2, but may also depend on start point (ie crap start = 2 pods). SMAX aliens always start with an extra colony pod.