I have idea for 2 mechs.
1. EMP mech. Medium mech with EMP ability to disable nearby mechs. Not sure if it should also disable friendlies.
2. Light mech and medium or heavy mech combo package. Light mech has a target designator to paint targets for larger mech. Larger mech shoots some sort of hellfire on steroids. Kind of like combining the damage of 2 secondaries. Haven't thought of their abilities yet.