I would imagine that up to 2000pts you get 1 FOC then at the 2001 you can then have two FOCs, I don't imagine that you would be forced to split it into two detachments i.e. 1001pts & 1000pts, you just get double the number of slots. That means SW could take loads of HQs
This being able to take multiple FOCs isn't new I think it was in 4th?