How useful would old ironclads have been in the First World War if Fisher had not disposed of them?
Short answerThey might have deterred isolated raiders or served in dangerous mine-clearing roles, but finding crews for obsolete ships would have been a serious cost.
NotesA few old ironclads might have served overseas as deterrents against isolated cruisers such as SMS Emden. They could also have joined the Dardanelles mine-clearing effort, where older hulls might accept risks unsuitable for modern ships. Neither role makes the vessels free capability because every retained ship still needs a crew. Fleet size cannot be assessed separately from trained manpower and mission value.