I would rephrase that and say that their games are permissive and allow players to do whatever and have fun. It is there if you want to use it, just like so many other absurd mechanics. At the same time, those mechanics are not something "real" in the game world; players can keep it realistic or they can try to innovate using what the game allows, but you won't see the goblins stacking dozens of crates to invade the Grove through a guard's blind spot.
That said, OP might be looking for scientific and historical accuracy in the wrong place. It's a fantasy game. They could have you spend an action to wrap an oiled rag around your weapon and then set it on fire, but also roll a saving throw every time you attack or defend, because your gauntlets are now slippery from handing the oiled rag.
