The point of the trench TDM is to be absolutely mean.
That way the enemy can't get an advantage.
Defend your builders, and make sure that builder knows how to pull out a weapon. (otherwise he's stupid and shouldn't be building)
Raid bases, destroy them. Rip them apart. If they can't stop you then your team is better. You now have an advantage because they have holes in their walls.
If you get banned for this, then the host is an idiot.