In the future, numbers will overwhelm both offense and defense. I can see where tactical drone 'motherships' may be more important to defense by providing low value targets to draw off fire by spoofing incoming ordinance, and where coordinated drone attack swarms could provide an advantage over even point defense weapons.
This is beyond mere bullets and bombs (and torpedos), and will require a little more science fiction in the rethink.
Smaller, faster, vessels with firepower multipliers will be essential, more stealthy, and easier to crew.