Fast battleships for threats on two sides of a country

Would fast battleships be the best response to battleship and battlecruiser threats on opposite sides of a nation?

Versatile fast capital ships are favoured when a country cannot afford two specialised fleets for different naval threats.

Italy supplies the historical analogy for a country facing different naval pressures on separate coasts. France is presented as one major battle-fleet concern and Austria-Hungary as another developing threat. Francesco Caracciolo is used to illustrate a design intended to meet those requirements. The argument concerns combining roles and moving useful strength between theatres. It does not remove the need to have forces available on both sides.