In the zombie apocalypse, there was a practical rule: your base had to match your manpower. Trying to secure a supermarket with just five people didn't make sense. It was too big to handle, and a small group couldn't cover it effectively. The same goes for a big group occupying a two-story building. It was a lesson learned the hard way by some survivors from fiction, movies, and series.
With Operation Reclamation being successful, the Blackwatch Private Military Company has earned themselves a square kilometer of land. Such a huge area would be impossible to be covered by four hundred armed men, especially when the area is urban layout.
Richard knew this so he planned on doubling the size of his forces. The current limit of his force is 850 with 415 in active service. Not only that, he'll also add more military vehicles and aircraft.