Res 4 + k_ring(1) gave ~50-60km effective radius, causing Oldenburg to absorb Bremen (40km away) and destroying score differentiation. Res 5 + k_ring(1) gives ~24km — captures adjacent Gemeinden (Delmenhorst at 15km) without bleeding into unrelated cities at 40km+. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>