Are there any known weaknesses to the mecha-grunts in warzone?
A lot of weapons works well against him, though usually I avoid ballistic based such as AR, BR, etc…I usually go for explosive weapons, Incineration Cannon. Plasma Caster lvl2 works well I find.
Supposedly, the energy shield canopy can be broken to reveal the Grunt inside (it supposedly regenerates, too). Apparently, the Goblin also has a weak spot on the back.