I watched the documentary film version of Freakonomics on Neflix the other night, and it was very fascinating. Although there was no segment analyzing the behavior of miniature war gamers, there was an interesting segment talking about incentives and cheating. The economist was talking about how people will find a way to break any incentive system put in place to try and control behavior. A typical 40k tournament is essentially an incentive system to control player behavior. Painting scores are there to try and make us paint our armies. Sportsmanship is there to control the way we interact. Comp makes us obey the fluff. It's no surprise that there is a way to abuse all of theses systems.
If people are going to break your carefully crafted incentive systems, then why bother? Tournaments, for the most part, are fun to play in. You get to play the game in a manner different from the normal causal weekend games at the local game store. The trick is to not put too much additional complexity into the design. Every tournament pack that has ever made me ask what the TO was drinking when he wrote it has tried to use too much complexity to solve the problem of bad player behavior. A complex rule system for a tournament isn't necessarily going to stop people from abusing the spirit of the game anymore than a simple one.
As a software developer I know a few things about complex systems. The more elements you add causes the amount of interactions between those elements to grow exponentially. All those interactions are places when unexpected behavior can occur. They represent places where people can break the rules and get away with it.
It's been my observation that people will bend the rules just enough to get what they want. Cheating is essentially a lazy act, so you won't see people create complex ways to cheat simple systems. It's too much work. With a simple system, the ways to break it are obvious, so it becomes obvious to see when someone does it.
You also don't need complex systems for people to have fun. The escalation league I'm running is a good example of this. The league essentially has two rules sets. The first one can be explained in a few sentences. You play games, get points for winning, and then spend those points to gain rank. It's really not that much more complicated than that. The second is an optional campaign with special rules and missions. I almost always see people playing in the simple free form manner of the first rules set, than with the more complex campaign rules.
Another bit of wisdom carried over form software development is the distinction between a working solution and an elegant one. Most of what we can hope for is a good enough working solution. A tournament system that get's it right most of the time is good enough. And you don't need complexity for a most of the time solution. And if you keep refining the good enough solution, over time it may become an elegant one that works all the time..
So the moral of the story: Cheaters are going to cheat, so keep it simple and have fun despite them.