Something like a guided 155mm shell that could hit missile would be nice.
The Oto Melera 76/62 with DART/Strales should interest you then.
Smart munitions are good against high volume low speed incomings like Harpoon spam. Against super and hypersonics, smart munitions will do very little.
The insane RPM is to throw so much high explosive lead at an incoming so quickly you literally vaporise so much of it what’s left won’t cause much more than superficial damage akin to taking small arms fire.
The Leonardo company will respectfully disagree with you on this.
Smart munitions will require larger calibre which means slower ROF but it will come with longer range which will push the engagement envelope further out. This should allow for a bigger engagement window and less requirement to "obliterate" the incoming missile.
IMO, there are multiple solutions from the one end of ultimate smart guided munition being the anti-missile missile and down the gamut to smart/guided rounds to unguided wall of lead.
I respect the wall of lead argument especially when it comes to obliterating the incoming AShM to reduce the danger of secondary fragments. I have my reservations about the ability of dumb rounds against maneuvering targets.
It all boils down to the pro/con of each solution and the other layers of Fleet AD that support them.