What did I stumble upon today but the most marvelous site: Vici.org. It has fantastic maps of the whole area that I am looking to include in my campaign. Here is the first map I made from this site.
Map from Vici.org. Terrible white lettering over the map is all mine.
Here we see the Cohort Fort of Saalburg with the watchtowers associated with it and the milecastle/kleinkastle that also had the same unit - Lochmühle. Saalburg was the home of Cohors II Raetorum Civium Romanorum Equitata. This was an Auxiliary unit that was at least in part mounted. This fits in with my preference for a mixed unit. To the northeast, Lochmühle had elements of the same unit present. While the milefort to the southwest was a unit of Auxiliaries from Legio XXII.
The Cohors II Raetorum Civium Romanorum Equitata was a Cohors Quingenaria Equitata unit. Formed by six centuries of infantry (80 men each) and four turma of cavalry (30 men each). This matches with the size of the fort.
The fort of Saalburg is well documented and there are any number of diagrams showing what it would have been like.
Taken from http://www.saalburgmuseum.de/geschichte/kastellgeschichte.html
Just 200 meters from the back gate of the Saalburg fort is the lime itself. The German Wikipedia sites are actually really helpful here. There is a diagram of what the gate through the lime would have looked like near this fort.
taken from http://de.wikipedia.org/wiki/Datei:ORL_A_03_tab_10_pic_03_Limes%C3%BCbergang_Saalburg.jpg
The child fort at Lochmühle is another story. This is far less documented as what it would look like. The general size is known. It was a 18 meter by 22 meter rectangle. It was set back about 30 meters from the lime. The artists reconstruction is dubious in that some sources claim that this fort had only one gate and this shows two gates.
Image taken from http://upload.wikimedia.org/wikipedia/de/8/8b/Kleinkastell_Maisel_-_Kleinkastell_Lochm%C3%BChle_-_Ringwall_H%C3%BCnerber_069.JPG.
Basically if you take the drawing at face value, there are room for 4 tent parties and an officer in the truncated barracks as well as a storeroom, a workshop and an outdoor oven. So that works out to about 32 men plus a head NCO, just under half a century.
That just leaves the watchtowers. These would be temporary duty for about 8 men who would take turns manning the towers. These would be wood or stone structures of 3 stories in height with the entrance on the second floor. In addition to this, there would be the patrols. Plenty of things to be going on for a campaign.
I am putting an artificial dividing line for the towers to be at tower 3/63 for the purpose of the campaign. That would be as far to the southwest as the troops at Saalburg would have to patrol.
Now, if push really comes to shove and the forces at Saalburg need backup, they have to call out to Legio XXII Primigenia Pia Fidelis at Mogontiacum or Legio VIII Augusta at Argentoratum or even Legio III Italica at Castra Regina. This could come into play if I ever venture into 6mm miniatures for Romans.
I think my next step will be to make some terrain.