The strategy I used was similar to BoxOfSnoo's solution. Since you start with the units necessary to make a Piercer and an Unseen, I keep those units supplied with the same configuration. The Unseen lets your piercers get close enough to the enemy Frame to disconnect it, and you want to do that as much as possible in order to prevent it from charging on the surface and popping through the Omega. Secondly I found that trying to get my own frame through the little pass in the mountains right between the two bases was just about impossible. The height of the mountains makes it so that the Frame can't pass. What I had to do was build a network of energy cores and transmitters around the southern end of the mountain range. After my frame was charged I got it truckin' down that route at just as fast as those energy cores were complete. The 4 command centers help since it's advantageous to have 4 piercers to take out the enemy's vital infrastructure so your frame won't get hammered on arrival and you can also capture the Omega. I built the flying rocket units to respond to any threat from the enemy and turrets around the entire base to hold them off so they don't mess with my ability to get on top of the situation. It sucks if you're not paying attention to your transmitters and they get knocked out by those tanks, then your whole base is out of power and your Piercers vanish.