yep, the enemy balance is really off. there are a few situations where you end up facing about a dozen level 4 goblins; you are literally buried in dice. the kuo toa temple is another one, if you fail the difficult persuasion check you find yourself completely surrounded by 8-10 kuo toa and an angry redcap "god". the 2 super minotaurs also rough. Why they didn't think normal 5e minotaurs were enough of a challenge that they had to give them a leap attack and multiattacks I'm sure I don't know.
This brings me to my biggest issue with the game. It's like playing D&D that's DM'd by the biggest A-hole you know. A stickler for RAW and ruthless in combat encounters, curb-stomping any downed players.