Major lessons learned here. Our team had a massive income advantage and at times a 2:1 army advantage but was unable to finish the game for over 20 minutes after taking the map. I attribute this to two failures:
1) Lack of forward radar and spotting. NE team had radar towers directly on the cliff that was the front line. SW team was pushing blind. After the artillery switch a Sparrow and an advanced Radar helped but there were still important blind spots and the artillery accuracy suffered from lack of direct vision.
2) Lack of mobile, active anti-air. The Chainsaws, Threshers and Razors did their job keeping map control despite the air threat. The Crasher gangs were very effective when I brought them into play. But I wasn't moving my Crashers to support my own or my teammate's assaults, and as a result the assaults all tended to fall apart whenever Phoenixes showed up.