I'm thinking thunderlord will be a beast in horde. Combined with a defender titan running iron harvest (heavy kills spawn orbs) and ruin wings. Tons of heavy drops, lots of orbs for your team and thunderlord can mow through enemies like butter. Plus it frees your primary for fatebringer. Then depending on the layout of the map a sniper to shoot ammo pickups so you don't have to get close. Even if it's a crap sniper that's the only thing you'd use it for.