"some holes would be "drier" than others. At least with lubed threads, the variation between fasteners wiould be minimised & the clamping pressure, even if slightly "off spec" "

What u are saying kind of makes sense. The bolts in your engine may have a smaller variatian in bolt stretch. HOwever.........How does the manufacturer of the bolt,,,know which grease u are using. However you increase the variatian between DIFFERENT ENGINES.
Anybody out there, corectly if I'm wrong... but this is my $2.67 worth...

The manufacturer works out the clamping load required. They then work out the torque required to give the clamping load.
When u tighten a bolt, the bolt stretches, the manufacture works out how much the bolt will stretch for a given input torque. (ie the reading on your torque wrench)
As u tighten the bolt, friction is created between the bolt and the block. This causes the bolt to stretch and deforms the threads. As the threads deform, they increase the torque required to turn the bolt. etc
If you lube the THREADS.. you decrease the friction between the threads and the block..end result is that (for a gievn torque input) you end up stretching the bolt more. Worst case : bolt breaks.
The torque figures are given for CLEAN, DRY parts. nOt rusty, not oiled.