You know, it might have been pointed out but I didn't know about it. I always thought it was random, not hard coded to any particular path.
I'll whine to Derek about changing it. I'm pretty good at that.
I hope you give some serious thought to AI champion progression, it is a rather crucial idea that the AI can handle heroes in the current game mechanics.
As Altein said "It shouldn't be random", at least not entirely random, the AI should take a random choice based on current statistics (it shouldn't make heroes with 1 (non fire) or 0 spell paths a path of the mage for example, some random behaviour in an AI is healthy though, so people who play a lot like me can't always predict the move of the AI players.