Why did Sturdee disperse ships instead of reinforcing Cradock?

If Sturdee was a capable officer, why did he make such an odd deployment against von Spee?

He likely over-analyzed the possible escape routes and created fallback lines instead of concentrating enough force with Cradock to stop von Spee immediately.

The deployment does not prove that Sturdee was incapable. A competent planner can become absorbed in every route the enemy might take after breaking through, dispersing forces to cover each contingency. A senior reviewer or chief of staff was needed to ask why von Spee should be allowed past Cradock at all and to concentrate enough strength for the initial interception.