So it should come as no surprise that one of the most effective competitive builds coming from the Ork Codex revolves around a formation of at least 101 Ork bodies; the Green Tide. Coming from the Waaagh! Ghazghkull supplement, it consists of 10 units of Boyz and 1 Warboss, all jammed together as one unit. The unit gets hammer of wrath on charge rolls of 10 or higher, and if the Warboss is the warlord, can declare a Waaagh! every turn after the first.
Giving the Warboss the Big Boss Pole (Fearless) and adding in some Nobz with Power Klaws makes for an ultimate board control unit that can tie down and beat up just about anything an enemy can throw at them.
Add to that a couple support characters and the power level jumps substantially. Namely, a Warboss with Da Lucky Stikk, granting the entire unit +1 WS, and a Painboy, giving all 100+ models Feel No Pain.
From there, I think you can build out the Ork Detachment to taste. Looking at my collection, I'm coming up with an idea for a wall of Trukks and a Battlewagon to help zone out board areas and block charges, as well as some specialist Ork units for fun. Alternatively, if your collection allows, I could see doubling down on the numbers of boyz and having ObSec trukks and mobs of boyz running around, leaving hard decisions for an opponent - kill the small squads that are capturing objectives, or try to focus down the wall of boyz denying several objectives at once and beating up anything they come across.
In the end, the list I came up with, using my personal collection, looks like this:
- Green Tide Formation
- Warboss: Big Boss Pole, Power Klaw
- 5x9 Boyz + Nob with Power Klaw
- 5x10 Boyz
- Combined Arms Detachment
- Warboss: Power Klaw, Da Lucky Stikk
- 5 Burna Boyz: Trukk
- 10 Tankbustas: Trukk
- 2x10 Gretchin
- Dakkajet: 3 TL Supa Shootas, Flyboss
- 2xTrukks: Reinforced Ram
- Battlewagon: Reinforced Ram
- 10 Lootas
General tactics are to roll on the Strategic Warlord Traits table and hope for the D3 Infiltrating units, as that's pure comedy, and outflanking burnas seem good. The other traits are also useful. The two CAD HQs join the Green Tide and more or less run up the board taking control of major portions of the board. The Nobz and Bosses are interspersed in the middle of the squad, meaning they probably won't make the first round of combat with their klaws, but are also pretty safe from any damage the Tide takes.
The rest of the list is relatively mobile, built around harassing flanks and generally blowing stuff up. Adding a second CAD could up the ability of the Grots to hold backfield objectives and also add some redundancy to the characters in the Green Tide, by adding characters like Mad Doc Grotsnik for more fearless and redundant source of Feel No Pain. His Rampage rule seems better suited to a smaller unit though. A Dread Mob would also be amusing, but will start to run short on points (though it is possible - Green Tide as Listed, Dread Mob, CAD for Warboss and 2 grot units (180 points)).
While I'm not making any dramatic last minute switches to Orks for NOVA, I do think this would be fun to play from time to time.