Most mothball ships are no longer adequate. Probably the last that will ever be revived were the Iowa-class battleships during the Reagan years. Getting them active was very difficult, as many essential parts were no longer manufactured. Otherwise, most are scheduled to be scrapped.
It would be far cheaper to build new, destroyer sized ships. Unlike our current destroyers, that are of the size of cruisers, these would be the size of traditional destroyers, and a group of them would likely have a destroyer tender ship, to extend their mission range.
I thought we had a buttload of '70's and '80's-production Spruance and Perry types laid up. Not to mention a bunch of '70's-era 1052-class (Knox class) FFG's, which were the immediate predecessors of the Perry class.
Plus all the big DLG's re-rated CLG from the 60's and 70's -- the Belknaps and Dahlgrens and Harry Yarnalls; what happened to them?