Hi,
I best start my 2 cents here with the confession that I'm geographically challenged. So my suggestion might be completely off.
Looking at the maps you came up with so far (great work btw!), I was wondering why you'd put Kalare somewhere with a west coast. I can't remember a passage in the books where this is implied and I think that some of the problems you're running into might be solved if you switch Kalare to the south coast. The westernmost states would then be:
1. Antillus (north)
2. Placida (middle on the north-south axis, but clearly west, north of the Tiber)
3. Ceres (south, south of the Tiber, kind of a large west-east span, but not a lot of north-south)
4. Forcia
I'd put Kalare east of Forcia, with a south-coast only. Ceres would then be on the north of both Forcia and Kalare, those two states being longer on the north-south axis than the other way round.
The Blackhills could be a mountain range that divides the western southern states from the eastern ones, with just a couple of passes between them. I think that the Tiber river could have its source in the Blackhills, because the Tiber seems to be the border between Ceres and Placida, and the southern tip of Placida's lands - where the First Aleran was first stationed - was in the Blackhills as well, probably the northern tip of that mountain range.
With such an arrangement, you can more easily put the city of Ceres on the marching route between Kalare and Alera Imperia, with no other big obstacles between them - assuming that the Tiber isn't that large farther east and nearer its source. It'd also better explain how the First Aleran moved away from the theater of the war when they were ordered to guard the Elinarch and why Kalare would invite the Canim in the first place: his own lands would be far away from the threat and the Cane would only be a problem for his enemies Ceres and Placida.
If there's a reason Kalare has to be on the west coast, you can just ignore the stuff I've written.
