According to Mod these 5 ships are "Designed to deter aggression and maintain the security of the UK’s interests, the Type 31 frigates will deliver a warship presence across the globe." One per ocean I suppose!
Names: HMSs Venturer, Active, Bulldog, Formidable & Campbeltown, for me lack a common theme and the Class name is odd too.
Guess I'm an old traditionalist