Two games in a row now I've had the Spider Queen random event trigger while my sovereign, one champion, and a summoned sand golem were wandering around as a weak stack and two settlements to support them. The event plopped a number of epic rated spider stacks near my towns, and not long after that they started spawning strong stacks to wander around and trample over improvements.
I used the control-U cheat to see where the spider stacks were, and didn't see any near any of the AI towns.
Saw this too, ruined a game when the spiders killed 2 of my 3 towns.. and all encroached onto my capital... This is one of the random events I don't like so far due to experience of the huge stacks you see.
Random events should be able to scale the difficulty of the spawned stuff depending on number of turns with pacing speed, either that or scale it with current hero levels, / current stack sizes for players. Because this is pretty devastating right now to play with 4-5 of these huge spider stacks by turn 100
Sincerely
~ Kongdej