The Dutch 1913 battleship proposal

Would the Dutch 1913 battleship proposal have produced useful ships?

Yes; the designs were credible, but dependence on German yards made the programme vulnerable as European tensions rose.

The proposed Dutch ships were useful and technically sound, and Dutch designers had waited long enough to adopt proven ideas from other navies. The larger problem was procurement politics rather than the design itself. The Netherlands chose German yards partly to balance orders and diplomatic relationships between Germany and Britain. That choice exposed the programme to the worsening European situation and to the capacity available in the selected yards. British construction capacity might have advanced the ships far enough for completion and service before war disrupted the plan.