I just have to ask. Are they really THAT big? Tunguska is shown to be roughly a cylinder of no less 400 km in diameter and 2000 km height. That gives volume one order of magnitude HIGHER than if you took entire land area of Earth and build it up to 100m high.
Yes, you will use a lot of space for construction and other … but still.
Are you sure it’s not meter for the scale ? I havennt checked myself but ya 2000 km seems very unlikely, my country is like 1300 km × 700 hundred and we are 67 millions inhabitant, so it’s seems unlikely nomads motherships are this big.
I looked at it more than once 
It still says 2000 km
Which source are you reading that says it’s 2000km?
I’m looking at the preview for the Nomad sourcebook. On the first page they have a diagram with all the ships and a scale. Tunguska is shown to be a total of 20km tall. It is about 3km wide at the base at its narrowest point, and about 10km wide at the top.
I think the scale along the boarder of the Ship Schematics in some PDF versions is off (v8.1 20190116 goes up in increments on 100km on the scale)
v8.2 fixes things, you can find it in the “All the PDFs 2018” folder of BackerKit if you got your PDF’s that way.
Exactly what Raith wrote. I have scale of hundreds of kilometers.
So that was a mistake and is fixed in new version. Thanks!