Primarily (due to it's small amount of units), what I primarily try and do is use the Black Orcs to keep some units busy while the horde wanders around and kills things. The Giant exists to take care of other large monsters and the doom divers assault large units to whittle them down making them easier for the horde and black orcs to handle.
The problem I ran into last night was a friend built a 2200 Wood Elf army for Adepticon rules and he focused on 5-6 small units of Dryads, War Dancers, archers, etc... Now, our other friends went "*scoff* Wood Elves... pfft!".
Well, his archers had my Doom Divers dead after Round 1 and he was able to mobilize those small units like mad. First he flanked and murdered the Black Orcs and then moved everything against the horde. That being said, the horde was still 42 men strong and we were still in round 3 when the time ran out (and with around 1200 pts being in that horde I might've still been able to do some damage), but at tourney I would've lost at this point.
I'm just wondering if there's something I could've done to make them effective faster.