A European fleet balance of destroyers and frigates

Should European navies build more destroyers instead of so many different frigate classes?

They need both: frigates provide defensive ASW capability and numbers, while destroyers supply the broader high-end combat power; a rough planning ratio is two frigates per destroyer.

Frigates extend fleet mass and carry much of the anti-submarine and defensive workload, while destroyers provide the heavier air-defence and offensive component. A rough two-to-one frigate-to-destroyer ratio matches the proposed British force structure. Repeated delay and underinvestment in infrastructure are deeper European problems than the choice of one combatant label over another.