I really believe this cost structure can work actually.
Unit type Cost revised from 1st scale
Submarine 5 IPCs A2fs* D1 Permanent A2 first strike *against all surface vessels only, including DDs.
Destroyer 6 IPCs A2 D2 Block Sub’s Submerge and Stealth move on a 1:1 basis.
Transport 8 IPCs 1 hit, Last Strike @1…?, no Taken Last casualty rule…? Escape?
Cruiser 9 IPCs A3 D3, Shore Bombard 3, one time First Strike AA @1 capacity
Carrier 12 IPCs A0 D2, 2 hits, carry 2 planes, damaged still carry one?
Battleship 15 IPCs A4 D4, 2 hits, Shore Bombard 4, one time First Strike AA @1 capacity
Fighter 10 IPCS A3 D4 M4
SBR: A2 D2, interceptors always destroy bombers first.
Tactical Bomber 12 IPCS A4 D3 M4
TBR: A1fs Damage D6, can do escort mission without bombing AB or NB.
Strategic Bomber 12 IPCs A4 D1M6
SBR: AA A1fs up to two Fighters, whichever the lesser,
Damage : D6+2 /minimum damage 2 pts if hit by IC’s AA gun.
No damage when destroyed by intercepting Fighters.
All aircrafts can hit unsubmerged Submarines without Destroyer presence.
If an optional feature can be added in this enhanced A&A game, such as any planes vs planes on a 1 or 2 roll, planes should be 2 IPCs lower.