COs
top - Grit and eagle
middle - Sami (and whoever u want since u need just Sami)
bottom - Jess and (whoever you think is good down there)

Use sami to capture the 2 cites on ur side to stop the snow n then use them to launch missiles at near ur base at lots of enemies. Have Grit go to attack from far range until they break the pipes n then change to eagle to strengthen ur flying units and attack Grit might also be able to attack a copter with the lander if u postion ur units right. Have Jess move near the pipes but no too near or u get hit by artillery. Wait for the enemies to break the pipes and come through and and then u attack. If u do it right u sholud be able to destroy most of their units easily.