Well if they're going to use "Average" hp per level, then it should SAY "average" in the description, IMO. Especially given the monsters running around with massive HP, we should get MAXIMUM hp. :P (I mean, really, a level FOUR minotaur with 76 hp? Give me a BREAK. But that's another post.)
Actually, Minotaurs in 5e have 76 HP. They are monsters with 9d10 HP with 16 Constitution [9x5.5 HP +27 HP].
Anyhow, monsters in 5e also use average dice roll, such as 5.5 per d10 in this case, while the heroic player gets 6 per d10.
https://www.dndbeyond.com/monsters/minotaurIt has a Challenge Rating of 3, which is of course not a level. If BG3 currently says they are "level 4", that is sort of their own way of trying to give it a relative power indicator. This should mean that a party of level 4 characters should find a Minotaur challenging or not too easy. If there are many Minotaurs, it therefore should be really hard and dangerous indeed.
Their main weakness is low Dexterity and AC (in 5e anyhow) : so Grease, Ray of Ice, etc. Otherwise, they charge/gore you for a lot of damage.
Bane (divine spell) should also work well on them.