At the edge of darkness something stirred. As the Milky Way turned, its edges crackled, and with an explosion, the Machine fleet emerged.
Damaged, but not destroyed, the fleet sought planetfall to rebuild and expand. The Machines needed the resources to self-replicate, as they were programmed. And then they could move from planet to planet to strip each one of their resources and expand, as they were programmed.
The massive distances and damaged jump drives dictated a timeline of decades or even centuries to continue their quest. But they had time, and could wait to rebuild before seeking out that which they came here for.
The Overlords slumbered. The Matrix entity kept a tenuous connection to coordinate the tasks at hand. With planetfall, an Overlord would awaken. And then another, and then another. It was all simply a matter of time.