Correct speed with 500 arms? That is not a helpful statement since we don't know what the definition of "correct speed" is. What matters is to reduce the effect of a single stylus to below audibility. I don't think that anyone has been able to quantify what that specification is. But there is ample evidence that extremely small speed perturbations are audible.
It is is misnomer to assume that a massive platter fixes the stylus drag issue. A heavy platter results in a smaller perturbation spread over a longer period of time. A light platter will slow more but will recover more quickly. A heavy platter changes the problem but does nothing to eliminate it. I think that most people prefer the shallow but longer perturbation from a heavy platter, but ultimately it's a matter of taste, not superior stability.
It is is misnomer to assume that a massive platter fixes the stylus drag issue. A heavy platter results in a smaller perturbation spread over a longer period of time. A light platter will slow more but will recover more quickly. A heavy platter changes the problem but does nothing to eliminate it. I think that most people prefer the shallow but longer perturbation from a heavy platter, but ultimately it's a matter of taste, not superior stability.