[JeffF.]

The Battle of Five Armies resulted in the destruction of "three parts" of the Goblins of the North. In UT Tolkein uses "three parts" to describe a length of march that was 3/4 completed so it is reasonable to assume he means the same ratio in regards to the Orc losses. This was a major battle as Gandalf points out in UT and RotK Appendices and only involved 500 Dwarves (aside from Thorin's 13), 1000 Elf spearmen (presumable a similar number of archers) and enough men so that the Dwarves and Men were about the same number of elves (as the Dwarves and Men took one wing and the Elves the other). This battle involving about 4000 Elves, Men and Dwarves was considered a major battle and significant event and comparable to the final battle of the War of Orcs and Dwarves leading one to believe they were similar in scale.

Thorin states in the Hobbit that the Dwarves of Erebor did not feed themselves rather they depended on lucrative trade to bring in their foodstuffs. These facts and the series of disasters of Moria, Ered Mithrin, Erebor (which can only be compared to the decline of Arnor/Arthedain in scope) all point to small Dwarf numbers as opposed to large by the WotR. The North in particular seems to be underpopulated. Fonstad in her Atlas makes similar conclusions.

Only once is Khazud-Dum referred to as having numerous folk and this long before the string of disasters. Thereafter no mention is made of large Dwarf hosts, even during the War with the Orcs that army was of all seven Dwarf houses. For us who wish to believe in large Dwarf armies (believe it or not I am one) it would help if there was at least one referece or example of one in the Third Age.