Which destroyer options could follow Canada's River class?

If Canada cut its last three River-class ships and ordered six air-defense and land-attack destroyers instead, which design would be the best option?

No immediate switch makes sense; keep the economical homogeneous River fleet and reassess mature destroyer options in the late 2030s or 2040s.

The last ships in a production run are usually the least expensive, so canceling them sacrifices economies of scale before a replacement design is mature. River-class ships give Canada a useful general-purpose solution rather than a perfect specialist for any single mission. Future Type 83, American, or Japanese programs can be assessed when an air-warfare requirement becomes actionable in the late 2030s or 2040s. American designs would need particular scrutiny because their crew requirements are judged difficult for other navies to sustain in personnel and running costs. Canada's recent procurement friction also supports diversifying suppliers and support relationships rather than concentrating every dependency.