Why twelve guns help a battleship engage two targets

Does a battleship with four triple turrets gain a useful two-target engagement capability?

Yes; it can divide six-round ranging salvos into two three-shell groups and find the range on two ships more quickly.

A twelve-gun battleship can divide its fire effectively because three rounds are treated as the minimum useful ranging group. This allows a six-gun salvo to be split between two targets. With enough guns available, the ship can preserve spotting information while engaging both opponents. The design gains fire-control flexibility as well as a larger broadside.