Why German capital ships began with smaller guns

Why did German capital ships such as the Scharnhorst class carry relatively small guns?

Germany had eleven-inch guns available, while treaty-era disruption meant that larger fifteen-inch weapons and their production knowledge took time to rebuild.

German capital ships did not receive relatively small guns simply because a designer preferred them. The Treaty of Versailles and the interruption of heavy-warship construction eroded the industrial experience needed to produce larger weapons quickly. Eleven-inch guns were available for the Scharnhorst class while fifteen-inch systems still had to be redeveloped. A treaty can keep shaping design after its formal restrictions weaken because factories, tooling, and specialist knowledge cannot be restored on demand.