Terminators are essential for taking out shields fast. Also great for putting napalm on inactive building which can be brought down easily later due to the slow burn. They may not have booby trap but timebombs are essential in situations where you are close to putting down a building but don't want to kill your self on a big defender.
Lastly if you are an attacker then bury with big guns and collapse is a nightmare for a building with more than 6-7 people.
Honestly you need all classes working together for best results. No one class is best overall.