Part of the problem is that the stall itself probably isnt modeled correct. For a good reason, simulating the air flow around the wings when the aircraft is stalling would prob require a lot of computing power...
It's not just the stall. Which, by the way, they actually model with airflow over the wings in hundreds of points. It's pre-stall, it's post-stall, it's when you're in a hammerhead, and even back before in-flight spawn were given forward speed, you would fall down and have to turn on engine, pull gear up, and nose up. The only plane that couldn't do this was the Ta152. No matter what your loadout you would drop the tail instead of the nose. You could never recover and would plow into the earth while everyone else recovered and flew off. How HTC has it is severely tail heavy, and that throws the handling off when turn fighting like a P-39 does. It adds instability that otherwise wouldn't show up.