@Baron:
You answered a different question.
You are questionning Destroyer’s blocker ability.
Maybe, if a more accurate naval is needed, DD can only be used as blocker against Sub ; to block surface vessels you can house rule that Cruiser or bigger is needed.
That way, some Carriers will be needed to do so.I would disagree. I think I talked about how subs and DDs are way to effective (compared to CVs) when building a combat fleet. If you wanted to make the game historically correct in composing a combat fleet, you would simply count the number of carriers and their planes, and then almost completely disregard the other ships. A fair version of this would be to make it so that ships had AA only, and planes where the only thing that was allowed to fire at enemy ships in a fleet battle. It is difficult to grasp how dominant they where. Remember that UK sank half of the italian fleet using 20 gladiators in a nightraid.
Blocker ability cannot be a fruitful tactics if you have to commit costly units.
The OOB cost structure is made in a way that destroyer is first fodder/blocker.
12 IPCs Cruiser is a high cost and 10 IPCs Fg can be fodder but not blocker.
Commit Carrier as blocker, you need an additional unit such as Escort Carrier, CVE, around 10 IPCs.