Random events are cool but I just had a Deadly spider army (16 spiders in a single stack) appear from the Spider Queen event and immediately raze one of my 3 cities on turn 109.  I only had a single Weak stack of troops running around.   Even if I rushed troops from every city, there's no way I could have defended against that since the spiders spawned about 2 turns away.  

I could understand a few widows appearing this early and attacking a city but that was a bit much.  Either that or have something like this only have a possibility to occur later in the game.

Playing on normal world difficulty/challenging AI, more frequent random events (which I may set back to normal).