I can't remember, but I do think it was an interview with Jon Van Caneghem... Either in a book of game design, or magazine. I have to find it.

Similarly long time ago, read about how AOE (Age of Empires) used a lot of computers to play against each other, then do statistic which units actually got used. The idea was to rebalance the units such that all are almost equally used (well in terms of computer-ai play).

I think these two articles were both in the same book, so I'll have to dig.

HOMM3 is also my favourite game, along with Disciples. I'm a big turn-based strategy fan :)