Ralph walks with Newt, answering her question as they go, "Yep! They try to space 'em out where most planets are a short distance away if they need help. That way, the ones closer can arrive quickly, an' then the others are reinforcements an' backup as they arrive."

This base, however, was on the outskirts, and not close to many planets at all. There were quite a few spread out along the outskirts, not only to watch for dangerous things coming in, but to give some of the worn out Marines an easier job while they recover.