I'm boggled by one of the posts how does a gnoll get it's hands on an acid arrow. that just using an arrow should be the limit of it's intellegence.... that boggles me
1. Gnolls are not anymore or less stupid then a normal int 10 person. Some are but most aren't
2. Gnolls raid as a lifestyle, which means they learn about their weapons, and how to raid. It's their life, and how they get food, materials, etc.
I'm sorry but you're 100% wrong about that.
https://www.dndbeyond.com/monsters/gnoll Gnolls have 6 int, 4 less than a normal int 10 person. And sure, they raid as a lifestyle. But they're also described as feral. The combination of instantly knowing which party member has the lowest AC, exploiting acid arrow to reduce our ACs, and ignoring attacking us to get a high ground advantage is just too much.
Ummm, did I mention anything about lowest AC, or acid arrow? No I don't think I did. But I'm going to humor you, even though you read more into my post then I put.
Taking advantage of High Ground is not something based upon intellegience which is the score that covers book smarts, reading, writing, arithmetic, and other in D&D terms Scholarly persuits. Which is how it pertains to wizards being that they are focused upon book learning, and scholarly persuits. So the fact you wish to bring the wrong score into it means your wrong.
Wisdom on the other hand would be the better score in D&D terms to describe this knowledge based upon experiences, how well you note things, and then put them together. So as for your AC comment yes they would know by seeing the fact that your wizard isn't wearing any shiny hardshell that they can do damage to him, easier then your fighter in that shiny suit of armor. The same thing would apply to knowing that acid arrow hurts that shiny thing, making it easier to get through to the soft squishy bits. (Even though they really don't know why it is doing that)
Then there is learned behavior which is based solely upon ones experiences. So a young gnoll raiding with a Veteran is told to go stand there and shoot. Does so later on he is on level ground, and notices he's having to adjust his aim differently then what he did when he was on the hill. He's learning albiet slowly do to mental processes, but he has an advantage no google, or wiki. or anything pertaining to book learning. Instead he has first hand knowledge, because his very life depends upon it. So he has to learn these things in order to survive and he does. Then there is fact that not all gnolls have an int of 6, just like all humans dont' have an int of 10.
The intelligence and other attributes is for a normal gnoll, not the more elite, but the ones that make up a majority of community. They who learn from the smarter ones. Such as the shaman, and warlord. Who are in many ways mimicking the smart ones, and following the smarter ones orders.
If not even Homo sapiens would of long been wiped out, as by your standards anything with an int of 6 doesn't know shit, and can't make tactical choices, or formulate plans
https://roll20.net/compendium/dnd5e/Wolf#contentintellegence of four, 2 lower then Gnolls, are not even feral, but animals. Yet they form tactics, they learn by doing have no opposable thumbs, or fingers unlike gnolls. Yet many of their tactics are used by hunters, and have been used by hunters since the dawn of man.
Much I could add, but will wait.