Documentation on sub-models

There's something that I don't understand in the documentation in pict.md, where it says:

"Placing all hardware parameters into one sub-model produces fewer distinct hardware configurations and potentially lowers the cost of testing."

But the example shown (with { PLATFORM, CPUS, RAM, HDD } @ 3) seems to produce more distinct hardware configurations. Not fewer.

By my count:
{ PLATFORM, CPUS, RAM, HDD } @ 3 produces 28 hardware configurations (across 336 generated tests.)
{ PLATFORM, CPUS, RAM, HDD } @ 2 produces 10 hardware configurations (across 120 generated tests.)
No sub-models (for neither hardware nor software) produces 17 hardware configurations (across 17 generated tests.)

So what's happening here? Am I looking at the PICT results wrong, or at the documentation wrong? Or could the documentation be improved by changing this:
{ PLATFORM, CPUS, RAM, HDD } @ 3
... to this:
{ PLATFORM, CPUS, RAM, HDD } @ 2