I think bot spawning (at least in Hexen) is buggy. Unless I'm mistaken, you spawn a bot with the following console command:
addbot botmc1
where the first letter after "bot" is the character class, the "c" stands for "color" and the number for the color of the bot. Meaning above command should spawn a mage bot.
It happened several times that I spawned several bots from all classes, only one fighter among them and then I saw 3 fighters at once, and no mage or cleric. Am I doing something wrong or is there a bug somewhere in the code?