I feel like the point is being missed. It doesn't matter if there are warnings. There a million times in a game where players are warned against doing things- even staying alive (Fuck you, Nettie). There are multiple fights that are above the level and capability of players at there level with their current armor and weapons. It isn't fun. If you have to have the right party, be in the right place, and get the right rolls to survive the first round it's not a good fight. Also, it is in the game for us to encounter. Saying we should stay away from it seems like a silly things to say. Experience the game, but not that part!
Steamrolling or not having a challenge at all isn't fun for others either. I did 2 playthroughs of EA and while there were some difficult fights (which I enjoyed) none of them were impossible at the level I attempted them.
If you attempt the fight at a level where you are too low, it should be hard or even impossible without cheese but that doesn't mean it's bad game design. If they balance all fights in EA for a party of level 3 characters, I would be bored because the game showers you with XP. A fight with level 5 oppenents shouldn't be attempted with a party of level 3s.