Stars in Assault and Skirmish?
 

I saw in my Dropship that Assault and Skirmish have stars allocated to them. But when I played a rounds of Skirmish, I didn't get any (on Medium). Since these were DLC additions, do you need DLC to unlock the stars even though they're available with non-DLC maps?

I can confirm playing Assault or Skirmish will earn you stars with or without DLC