A Destroyer or Cruiser "swarm" can work, however it requires extreme teamwork, lots of practice and patience to successfully take on a battleship. Which is very difficult to get most skippers to calmly pull off such maneuvers. Also realize there is a high probability that one or more of those destroyers going up against a battle wagon would likely be sunk or seriously damaged in the process, however using torpedoes the destroyers are also very likely to be able to inflect enough damage to sink a battleship. Now in Big Gun Combat battleships would have to arm and activate as many of their secondary batteries as possible to fend off those annoying greyhounds nipping at their heels. Which is one of the reasons that battle wagons have secondary batteries to begin with. Thus making it very difficult for destroyers to get into their own gun range (which is pretty much suicide), or to sneak up along side for a torpedo attack. Plus rotating turrets have a major advantage over fixed guns in keeping those little torpedo buggers at bay.