That's crazy. In a good way. I decided to go with the Kafers, bought the sourcebook. Started converting their vehicles to T2k v2.2 stats. My plan is that since they see humanity as their mythical "boogeyman", they're attacking Earth as a preemptive strike, to try and rid the universe of them.
They just come smack-down into the middle of a broiling world, two steps from WWIII.
And they really enjoy a "good fight", so I feel like they won't nuke humans before they land, but instead challenge them with their military might. If/when humans become a REAL problem, they'll resort to nuclear bombing.
I also thought that they might attack weapons silos and manufacturing facilities, but leave population centers alone because of their nature revolving around "troops" and others.
The more people alive, the better the fight y'know?
EDIT: I've been using Random.org's geographic coordinate random generator to decide on some initial landing zones. The 'winner' so far? North Africa/Middle East. Might have to incorporate some RDF in there!