And iiiiinteresting quote he references:
‘Not a beggar,’ said Aragorn. ‘Say a captain of the Rangers, who are unused to cities and houses of stone.’ And he commanded that his banner should be furled; and he did off the Star of the North Kingdom and gave it to the keeping of the sons of Elrond.
- ROTK Bk V Chapter 8 The Houses of Healing
.... I'm thinking I'm going to read that as a bit poetic - meaning rather that the Dunedain of the North no longer maintain grand dwellings and fortresses, not that they've lost the art of throwing up a fieldstone cottage.
The question of numbers is such a tantalizing just-out-of-reach topic though! Mr. Martinez' suppositions seem supportable, but I do hope something more definitive crops up at some point from all those papers.