New York: Defeating

1. If you have an opportunity to do damage, take it immediately. It might be a long time until you get that chance again.
2. Gauss guns are great for picking apart New York’s defenses. You can damage their tough units and the base at the same time. 
3. If you have Push-Backs, try to keep at least one unit next to NY's defenses at all times, even if it's not attacking. This way Push-Backs can more often be taken advantage of.
4. If you have a Ranged Damage module, make use of it. Being able to kill NY pieces at range with one hit will make the fight much easier.