Hi JeffF and all,
slowly catching up with all this that was going on while I was travelling.
First a few old threads that may be useful for the discussion-
How Many in the Battle of the Five Armies?
Soldiers Available in ME
Gondor: Population and Casualties
A few extra thoughts-
Rohan could raise about 10,000 infantry (local militia probably) as well as the eoreds.
Gondor -really tricky! When were the 'Days of Power' that Imrahil mentions? We don't know which Age that he's referring to even.
The Fiefs might be able to raise 30,000 as 3,000 at MT are a tithe of their strength, unless this was an exaggeration!
By total guesswork I reckon that Minas Tirith City itself might raise something around 12,000 men, the crazy guess being - MT could hold 100,000 people based on historical cities, but this is within an order of magnitude! (not as low as 10,000, almost definitely less than 1 million). By LoTR it contained half that number ie 50,000 people, half male ie 25,000, maybe half of fighting age so about 12,000. OK this could be a lot lower or higher, but you get my drift. JeffF's estimate sounds within a range I'd be happy with.
Dain, Thranduil, Lothlorien, Woodmen & Beornings and High Elves I'd agree with. Remember Isildur was 3000 years ago so a lot would have changed in that time!
Dale I'd reckon a bit bigger after their recent expansion, Woses maybe fewer.
Hobbits - less than a few hundred bounders and shirrifs, but thousands of partly-armed hobbitry when 'roused'.
Saruman - I'd go for the higher estimate, as the 10,000 orcs were those at Helm's Deep, therefore not counting any casualties and detachments involved in the Fords of the Isen, Ugluk et al, and the men and halforcs of various types.
Sauron -
waylaying the East Road - spot on.
Attack on Minas Tirith, I think huuuge numbers, but 80-90% of them comparativley useless orcs and snagas. I think PJ computer-generated about 200,000 to make it look like a big army, not that this means much
. Nice mention of the Siege of Vienna by Tuor, similarly huge besieging army but mostly composed of unenthusiastic conscripts around a small core of good troops. If I remember it was said that they chained artillerymen to their guns to stop them running away, which sounds unpromising! Also echoes of Byzantium in my mind.
Dol Guldur - likely a lot more, it was re-occupied with sevenfold strength after the White Council threw out the Necromancer at the time of The Hobbit. As JeffF said, in LoTR they mounted a number of attacks and got beaten each time, possibly split their forces? Cardinal error! Lack of Nazgul direction?
Easterlings etc - would agree with Kuru that the Sauronic numbers here should be larger though would be less inclined to increase the Dwarf and Dale (and Laketown) numbers so much. Would also imagine orcish allies turning up from the old holds that could have regained their population after Bo5A.
Black Gate- 'ten times and more than ten times' - a problematical phrase. Could mean 10x (ie 60,000), 10x plus a bit more (70-80,000), 10x plus 10x plus a bit more (around 150,000) or even 10x x 10x plus a bit, (700,000!!! - not v likely). I'd go for one of the middle estimates, clearly the Allies were going to be wiped out unless the Ring was destroyed.
I guess the key thing is that the majority of the Sauronic forces are orcs that are clearly qualitatively inferior to most troops (eg Denethor surprised that Boromir was slain by orcs alone, relative casualties in Eomer's battle, etc etc). Think Challenger or Abrams tanks versus T55s !