Well, what do you mean "truly good"? If you had an enormous, worldwide, yearly tournament of Game X and gave the winner a million dollars each time, after ten years I think you'd have to say that the winner was "truly good". Can you say that the person who, right now, is the best at Fallen Enchantress (however you want to determine that) is not "truly good" at the game? I think you have to say he (or she) is. I think you probably could design an AI to be better than humans at any given game, but it would probably take as long to write that AI as it has to write the best chess AIs. The more funny rules the easier it is for a human to see some little trick that just lays an AI flat. I think anyone who's ever had to write an AI for an actual game that needs to be released at some actual point in time would strongly disagree with the statement that "the real challenge would be to make the AI capable of sucking".
According to this thread you know nothing about AI, and you are "impressed" with the Overmind. Have you ever had to write an AI for a game that was released? No? Please tell me more about how you can read the minds of people who have.
The best FE player is not good at FE. Did you want me to deny that? Sorry. TBS games are the strategy game most optimized for humans. You can use various tools, including paper and pencil and spread sheets and you have effectively infinite time to plan your moves. But we are still bad at them. Humans just are good at keeping track of so many things, that's why you have to use tools. Are there a few people with non-neurotypical brains who are exceptional at TBS games? Maybe. But that doesn't mean humans as a species are.
Computers are super amazing at all the parts of TBS games that people aren't. Keeping perfect records of dozens of statistics about hundreds or thousands of unit types and buildings and spells for instance. Never ever forgetting part of their plan. After all that's how programming works. Computers follow perfectly, every time for millions and billions and trillions of times, the instructions that a human gave them. They never forget one, or mess it up.
Now imagine if humans had to do all this stuff in real time like an RTS. The Overmind does something that most computer AI doesn't although people are finally starting to do it, it calculates optimal targets based on how hard they hit and need to be hit and how fast they do so. Humans can't do that. Have you seen the mental math skills of the average human? Its embarrassing to be the same species as them. Sure you can memorize the stats of star crafts few dozen units and its 3 lousy tech levels but anything more complex than that isn't gonna be too great. Imagine trying to run a Dom3 battle in real time. Its practically impossible for most people. Dozens of buffs each modified by the magic level of the caster which can be further modified by other buffs and then dozens of resists and shit.
And although Starcraft games are specifically designed to be balanced for humans and simple enough for humans to understand, they still aren't balanced because computers don't play by the same rules. The Overmind massively abuses mutalisks which are balanced because they are so hard to control. As they note in the article you posted humans simply can't micro mutalisks that hard. Also if you read the article you would know that the Overmind had its own pathfinding as well.
There are a lot of other barriers to computer AI. For one thing the AI has to run on the same machine, until recently on a single core, with the graphics and simulation state and other crap. The human player has its own million year tested computer whose eccentricities computer games are designed around that has no other tasks in play. What if you had an entire computer that was set up to run the AI and send only its command to the computer managing the simulation state? This would also preclude other processes eating up system resources.
In fact contrary to popular belief it is the humans who cheat the most at human vs AI games and not the AI.
Now even if we don't give the AI its own computer, since financially its not possible, there are still hundreds of things we can do that can make the computer more effective. The Overmind made only a few major changes to the way the AI works.
The reason that the real problem is making the AI dumb is because it has to be believable. The AI needs to vary its mistakes as humans do, making different ones each time. The AI needs to know the proper progression of skills for humans to learn the game so that as the AI raises in difficulty it prepares the human for multiplayer. Remember that poor human players are just as easily exploitable by a single trick that knocks them flat as poor AI players. A Zerg rush will crush a new human player quite easily over and over.
