Seems the Allied won't be allowed to take off until we break dar. As such I'd recommend we come in at 19 000 ft with the B5N2 "Kate" bomber which has a bombardier view. The higher we are the longer it will take the lumbering P-40B to climb to our altitude. Also the higher we are the bigger advantage our Zeros have against the P-40B, and especially against the P-36C. Best approach for line up would be from southwest of the Harbour, best approach for least time on DAR until we can drop is straight from the south of the harbour.
I've made bombing tests. You need either 4x 250 kg bombs or 2x 500 kg or 2x 800 kg of bombs to kill any of the dark-grey and tan colored destroyers. The only exception is the brown ship at the dock at F18 which need half the amount, so a single B5N2 can go for this F18-ship. The B5N2 can carry either 2x 250 kg or 1x 500 kg or 1x 800 kg. With wingmen in trail/inverted ladder formation you could get lucky and sink one ship yourself. I recommend though a loadout of 1x 800 kg, and have two guys go for each ship to make sure we sink it.
1st sortie I recommend lots of B5N2's, with the 352nd as escorts in Zeros. Approach at 19000 ft from S or SW of Pearl. Egress south after dropping and get back to the CV's once clear.
2nd sortie I'd recommend a large contingent of fighters, just battle for air superiority, with some volunteers to fly B5N2's and come in as high as possible to finish off the remaining ships. Again the higher we fight the better off we are, so our Zeros should always strive to come in high.
Cheers!
/Robert