And I am thinking the strategic logic behind larger ships for small/medium navies are becoming more and more unsound with the induction supersonic/hypersonic AShM or HGV in the near future.
If what you imply as small/medium include the Italian navy, then imo you are wrong. While Italy is not a superpower, I do not consider its naval arm the
Marina Militaire (MM) to be in the league of the small or medium. Yes medium in size but not the scope and responsibility.
All great power navies has one
raison d'etre that is sea control. That is to control a particular body of water while at the same time denying its use by the enemy partially or completely. For that you would want the biggest fleet, the biggest hulls and the most advanced technology available to be put to sea.
As a single nation and seeing from a single nation perspective. Italy's naval arm, the
Marina Militaire isn't sufficient to do sea control, but as part of the larger NATO alliance, the MM is compelled to achieve sea control in alliance with other members. For that they'll need a very big ship able to stay at sea for a very long period of time and deep enough magazine. While at peace this is useful to maintain order and in war its useful to achieve sea control. And in this case this objective (sea control) is something that is achievable with the collective might of NATO members.
For the other side, once sea control is not realistically achievable, the one course of action is sea denial that is to deny your enemy control at all cost while not trying to achieve one.
And this sea denial is what the "real" small/medium navy , the likes of Bangladesh, Indonesia, Malaysia, South Africa is realistically build for. For them a naval arms race is a dreadnought moment, they'll never be able to catch up let alone level the playing field. So for them having big ships the likes of Arleigh Burkes, Type 45s are not as crucial. For them as long as the enemy couldn't freely use the sea or kept the other side as fleet in being is enough. Hence many of these countries opted for corvettes or frigates and some coastal defense weapons.
So this has nothing to do with hypersonic tech being proliferated. Even though to be honest anti HGV test is something that is currently being tested in destroyer class ships.
People like to talk on why the German F125s is such a dumb project without realizing the true purpose on why Germany build such a big ship with very light armaments. Because for them the priority is presence at sea as long as possible with less time docking. And I'm quite realistic when I said that in the intended area of operation, they will not find anything of opposition that couldn't be handled by RBS-15 and RIM-116s.