That you are meditating on "fun" is the important thing.
In a Frog God Games Organized Play (PF 1e campaign branch) this past spring, "Mountains of Madness," the GM thought it would be fun for the enemies in a mine (hobgoblins?) to alert the entire chain of command, including a shaman with a Hold Person wand (with enough charges contained for the full party) and his undead along with elite units, to the arrival of our third-level party. We all died fighting with the exception of our rogue, who managed to hide in shadows long enough for the couple units pincering us from behind to pass him so that he had a chance to flee in order to bring another party to the gristmill to face our undead corpses.
I'm not sure whether this combat was as described in the book of the same title. The GM did do some foreshadowing as he described movements of enemies that we couldn't see, which I pretty much ignored since my character would have no idea what was going on elsewhere in the lair. It was a fun battle, but I was attached to my campaign character. That would not have kept me from playing more (I did consider it), but I ended up being too busy to commit to the current sessions.