Orks are not competitive. Sorry.
I'll give you a second to lift your jaws off the floor.
Good? Great.
This has been covered before, but I'm kinda sick of going over it again and again.
Here's some good reading on the subject:
[URL="http://bnhblog.blogspot.com/2009/09/competitive-orks-paradox.html"]Orks[/URL]
[URL="http://imperiusdominatus.blogspot.com/search/label/Orks"]Aren't[/URL]
[URL="http://www.baldandscreaming.com/commentary/greenskins-versus-meta-game-are-orks-competitive/"]Competitive [/URL]
Read through all that if you dare and let's see if we can get a good discussion going.