I summed this up in case anyone was interested… this includes AAA so it may be a bit skewed.
Japan: 556 +26 income
USA: 203 +17 income
UK: 106 +16 income
ANZAC: 84 +10 income
China: 61 +12 income
destroyers are the best for blocking, essentially trading and sacrificing units. Although it’s not a historically realistic tactic, it works in this incarnation of the AA games.
What about using DDs in conjunctiion with SSs? The subs can soak hits in the early rounds right, for only 6 IPCs instead of 8 IPCs. I understand the extra #3 attack over a #2 gives the DDs a slight plus for the IPC cost, but i think adding a couple subs could give a small bonus to the final numbers.