What related warship designs would share

How much technology would an armoured cruiser with sixteen 9.2-inch guns share with an Invincible-class battlecruiser?

The designs would share engines and fire control, with relatively limited interchange beyond those major systems.

Propulsion and fire control are the most likely systems to be shared between contemporaneous armoured-cruiser and battlecruiser projects. Engines would provide the main shared machinery, while fire-control equipment could transfer across both designs. Some additional overlap is possible, though it would be limited. Related projects could therefore reuse key technology without making their wider designs interchangeable.