Beating Orks ain't that hard. All you got to do is take bigger more greener Orks and kick those puny gits heads in!
Or if your not an ork, use an bait unit. Orks charge 8 gaunts, kill them, then get barb strangled to death.
Counter charge.
Orks charge unit and fail to wipe it. Next turn, hit it with your counter charge unit. Make sure to aim away from the Powerclaw when counter-charging.
Deny the charge.
Remember Orks are no good if they arn't charging. Charge a 30 man unit from the side/back and watch them flounder as the PK nob can't make it to the battle.
Don't be afraid,
Don't worry a unit of 8 Berzerkers will still. beat an 30 man ork unit on the charge. Stick to your plan and don't give up before the game starts.
Bring the fight to them!
Charge you bikes, fast unit right at the lootas. Either he watse shots trying to save them or re-routes one of his 30 man units.
Beat them silly.
Fights with orks are always bloody. Pick a 30 Ork unit, and blast it with everything you have....Everything. Focus fire breaks Orks. Then charge the remains. Even if you don't win, the ork player will send back up, kill the unit, and be all bunched together just waiting for some pie plates and flame templates.
Good Ork Hunting!