I feel like I'm being trolled by moderator.
If you spec slayer to have 700 toughness and 2500 armor (you'll have to avoid using career mechanics for that), use your renown points to reduce incoming damage, you'll sacrifice great amount of strength and weapon skill. Means your slayer will be tanky but will have really hard times killing.
Though, if you'll use 2h, you'll be able to kill easier as 2h compensates a lot of strength.
The complains are about "mara with GoM can't be killed". It comes with the price. It doesn't come with just switching to GoM.
It's same thing with Zealot/RP. You are not turning into full-scale DPS as you switch stance mid-combat. You just allow yourself to use stagger with bit less disrupt chance.
Choppa and slayer are bad example as their high-burst abilities are bound to 2h. Also their career mechanics reduces their survivability.
Better example would be def DoK/WP as DPS.