I am back to being baffled with what you are arguing about.The other is at least as falsifiable as conservation of angular momentum. And of what avail is a predictable assumption if you have no idea if the prediction is correct or not? (And you have no idea if the assumption lacks proper justification.)
I still do not agree with your claim, that the 3rd law conserves angular momentum if you just assume the additional restriction of the direction of forces. It is your assumption that, together with the 3rd law, conserves angular momentum. Such a restriction must be justified (e.g. by experimental observations). If you just assume it than the resulting conservation of momentum is an assumption as well.