Depends on your goal. I love making my orks as random as possible. Trukks for Kerreen. Looted wagons with the don't push that red button. Shokk Attack Gun for the truly spectacular win or fail. Etc.
Well that's true. If randomness is your goal, then weirdboys/warpheads are the way to go. I think however, that
Widowmaker666 was asking for how to make his list more competitive. To do that, it would be helpful to point out the balance of randomness -vs- helpfulness. With that in mind...
A SAG: Always shoots, and odds are (most of the time) the result will be helpful and not disastrous.
A Trukk: Always moves, and if it does get wrecked/exploded, actually has a two thirds chance of something positive happening!
A Looted Wagon: Odds are, most of the time anyway, will do what you want it to. In fact, there's only a 1 in 6 chance it will not.
A Weirdboy/Warphead: Whereas a SAG always shoots, or a Trukk always moves, or a Looted Wagon (most of the time) will always do what you kitted it out to do... a Wierdboy on the other hand, will hardly ever do what you need when you need it.
"I need a Zzap result right now so I can blow up that tank." Well, unfortunately, you only have a 1 in 6 chance of rolling Zzap. Upgrading to a warphead helps, but ultimately only gives you another 1 in 6 chance to get what you need.
There are some pluses however. All his powers, save one ('Eadbanger), have a really positive affect. One of them even affecting your entire army!
In the end, my main problem isn't even with unpredictability, but rather that he takes up a valuable HQ slot. With Warbosses and Big Mek's as the other choices, I can hardly imagine why you'd burn such an important slot on such an unpredictable unit.
Unless of course, your whole desire is to achieve randomness... :wink: