Could a Royal Navy armoured-cruiser squadron have seriously threatened Goeben?
Short answerYes under favourable close-range or night conditions, especially with torpedoes, though the cruisers would risk heavy losses and might only slow Goeben for heavier pursuers.
NotesFavourable conditions could let several armoured cruisers converge from different directions and use both guns and torpedoes against Goeben. The battlecruiser would probably win a conventional fight, but it did not have protection to ignore repeated hits or a close torpedo attack. Even damage short of a sinking could reduce its speed enough for British pre-dreadnoughts or battlecruisers to catch it. A numerically abundant but obsolescent force could therefore still matter as an expendable delaying threat.