How many Alerans to eat it? Hard to say: we don't know at all the initial population and have a vague idea of what's left of it. The best they could field after 6 months of mobilization was about 300,000 legionares total, so I'd say maybe 3-4 million Aleran survivors, including a lot of women and children. Oh, and add 700,000 Canim, who are probably worth about 3 Alerans each, though Varg and Tavi would argue the point.
Mmmmmsorta.
The vord expansion, as you noted, happened along the causeways and was aimed at the major cities. The big thing that tactic did for the Vord was to neutralize Alera's shipping/mobility/communications. I mean sure, you could still send things by flier, or by water, but it that's gonna limit communications to the government and very wealthy businesses. So during the course of the vord invasion, the vast majority of Alerans, on their steadholts and in their small towns, cut off from the whole rest of the world, basically sat around having no freaking idea what was going on.
The vord basically isolated Alera into districts, surrounded by barriers of croach built up along the causeways, and as they cut each district off from the rest of Alera, they neutralized the manpower and much of the furypower resources of that district. 300,000 legionares wasn't the number of able bodied men who were left in Alera (also, their support structure doesn't work at the general 10:1 rule of thumb, due to the fact that furycraft figures so prominently in their operations, and that furycraft availability has a hard upper limit instead of being a function of population size). 300,000 was the number of men they could get equipment to, but they were turning out equipment at the approximate rate of a Legion's worth of gear a week.
(The problem, eventually, would have been having enough Knight-level and higher support for each legion, but that's another issue entirely.)
Anyway, while there were around three million refugee/host Alerans up there in the NE corner of the continent at the end of FLF, there were four or even five times that many Alerans left in the nation as a whole--the great majority of them being freemen and the lower ranks of the Citizenry who were cut off in those isolated districts which the Vord had not (yet) had time to overrun. The Vord Queen's offer of clemency for Alerans who surrendered similarly resulted in a LOT fewer deaths than there might have been.
After all, once the folks with the strength to resist were put down, the rest could be disposed of whenever.
Anyway, the real problem Alera faces after FLF is infrastructure. The roads are shot to hell in many ways. The best farmland has been converted to croachland. Trade patterns have essentially been blasted back to stone age, so to speak. It's going to be a long, long time before it's going to be possible to get things that you really need on your farms (say, the plowshares that were manufactured in Forcia that you absolutely NEEDED if you want to break ground around Phrygia or Antillus) moved from their manufactories to the actual market. Quality of life is going to take a huge hit, just because the only stuff you'll be able to purchase will be the things within walking distance. And it's going to be a long, long time before, metaphorically speaking, the shelves at Wal-Mart are reliably filled again.
But what a boring book that would make.
The really fun stories to write would be:
1) Tales of the Vord War, where people with little or no furycraft suddenly find themselves fighting a war of resistance against an enemy that's all around them--which was critical, by the way, and forced the Vord to keep thousands upon thousands of their troops on security duty, to keep their supply lines from being cut. The little guy made all the difference in the final events of First Lord's Fury. (It would make a really cool mmorpg.)
2) The conservative revolution that rolls in about five years after Tavi becomes First Lord, powered by a lot of major moneyhouses and disaffected nobles who are able to rally support around a "kick out all the aliens" banner. Lotta politics in that one, though, with dirty underhanded sneakery dominating the day, rather than epic battlefieldiness.
3) The Canim. As far as storytelling craft goes, the Canim kick ass. They are always at some kind of war with something.
4) About 150 years later, when Alera looks a lot more steampunky than it does currently--and when the ancient enemies of the Vord show up to scour the face of the world clean of them.
We'll see if I ever write any of these stories. But they happen in my head.
