Good point, Headran. These values you presented correspond exactly (after metric translation!) to those given in our WDM (Table 9.5.1A) for horizontal diaphragms over D. Fir/Larch framing. However the final entry in this Canadian table is for 5/8" ply (15.5 mm), using 3" nails (10 D, having 3.7 mm dia.). This table does not go up to even 3/4" ply.
Using larger nails than 3" in these 5/8" panels will not result in greater shear resistance, this is true. But is this not due to the fact that it is the various shear resistances within the panel itself that govern the assembly? While the shear resistance of thicker spikes is greater, what good will it do to "walk the nails to the panel" if Vr(max) has already been reached by the panel itself? Incidentally, the WDM also deals with shearwalls and diaphragms using diagonal 19 mm (3/4"

and 38 mm (1.5"

boarding - Clause 9.5.1.1 The 19 mm boarding is specified with 2.5" common nails (8-penny), and the 1.5" boarding uses 3.5" (16-penny).
As far as I can see, the reason the shearwall tables do not specifically deal with configurations using thicker panels is that these applications are rare, and testing costs money. While the data is there for shear in an individual plywood sheet, (refer to my first post), it is not yet available to us for shearwall and diaphragm assemblies. Does anyone else have any information on this? Sustainable, Solar, Environmental, and Structural Engineering: Appropriate technologies for a planet in stress.