I'm not a P&P player so I don't really care about the game being absolutely accurate... But "I know" (probably not everything) the rules and the more I think about it, the more I think the game would be far more fun (subjective), tactical, balanced in many ways and so on if they started to create a D&D game in which they implement their systems instead of thinking about how they could implement D&D in them.
Now this I can agree with. Larian started at the wrong end. And it might be as people claim that they were working on DOS3 when they got the lisence for Baldur's Gate, and had to change a lot on the fly.
Now I'm no programmer, but I don't really see how hard it is to just take the players handbook and start implementing the ruleset as is?
I personally don't mind "homebrew" monsters, but it should be pointed out that the Monsters in the Monsters manual is very very well put together mathematically, it all makes sense. Thing is: There's way to few of each monster. So you want to homebrew to get more variation. But at least start with the standard basis for a goblin, and go from there...