I use Sgt Forge and build four supply pads, two reactors, and a vheicle depot. I only train scorpions and never upgrade. I can have three ofr four scorpions on the ground in no time . I rush with the scorpions and keep building more in the mean time. It works great! I havent lost a match yet since ive started using this strategy. It does hit a snag once in a while but since I have already established scorpions all i have to do Is upgrade and it always works.