First of all, we need to make a correct definition of the GENERAL differense between a Panzer Division and a Panzergrenadier Division. A Pz. Gr. Division contained ONE battalion of armor (usually tank destroyers, except for the elite formations which actually received tanks), while a typical Panzer Division usually contained TWO armored battalions (the common composition was one battalion of Panther tanks and one battalion Mark IV's). These examples are from two divisions in 1944.
Another important differense regarding these types of division is their transportation of infantry units. A pure Panzer Division typically (but not always) were supplied with SPW's for their infantry battalions, in order to allow them following the armored units into battle. On the other hand, the infantry battalions of Pz. Gr. Divisions were equipped with trucks instead of SPW's, mostly due to shortages.
Now, my suggestion is that Pz. Gr. divisions only count as 2 stacking points, while maintaining the 3 stacking points for an armored division. Any suggestions or comments?
Regards, Rundstedt
PS. Kuniwoth, I hope this was intelligent enough for you?