I recommend using Eagle as one of the COs (to get him to have to choose Sami for all the Green Earth missions). His Lightning Strike is very useful at the beginning to drive back sturms forces. Just bunch together the units for whoever you have on for the Blue army (Max, Grit or Olaf), well at least until you can get out the first Lightning Strike. After that just watch out for when Sturm is going to use it again and bunch some blue mid tanks and bombers together (it is based on how much the total units cost, not on how many there are).