Does Japan have enough land based planes (not including BETTies) to succesfully attack Allied CVs? There should be two large KATE units in Japan, and one small in China. There is one, small, unrestricted VAL unit, and another, large, in Japan. How many of them non-permanently restricted? If all, that should be around 100 anti-ship planes - not enough. Sending more BETTies is throwing out map coverage, so first proposition would generate too much unnecessary loses, and will halt pilot training.
There are troops in Palmyra, but they can not start building forts, before they repair base first. It would be easy to keep base damaged all the time.
Firstly, as an experiment:
Anchor KB in Palmyra. Lets see how many CATALINAs get through 300 strong KB CAP
I checked 3rd Marine Division composition in WITP sheet, maybe it is different in AE. Anyway, largest guns are only 105mm (in case of defending from bombardments), and they have no organic AA defence.
Loses so far, for three days of combat (first include tank unit):
Squads: 29 destroyed, 13 disabled
Non Combat: 96 destroyed, 22 disabled
Engineers: 7 destroyed, 0 disabled
Vehicles lost 64 (63 destroyed, 1 disabled)
Squads: 36 destroyed, 35 disabled
Non Combat: 45 destroyed, 34 disabled
Engineers: 3 destroyed, 3 disabled
Vehicles lost 18 (9 destroyed, 9 disabled)
Squads: 7 destroyed, 12 disabled
Non Combat: 19 destroyed, 43 disabled
Engineers: 0 destroyed, 1 disabled
Vehicles lost 12 (2 destroyed, 10 disabled)
So, around 100 squads destroyed (that is 1/3rd of original 300), and 50 disabled. Division is at half infantry strength, not counting loses during landing. 150 non-combat destroyed, and 100 disabled - this is half of support. Engineer loses are deepening repair problems. So Division have now less than 50% AV.
Overstack demands 20% more supply for every 10% overstacking people. So they are eating 300-400% now.
You can not turn off repairs, so until then - no forts. Repairs use supplies, and to ensure they will never repair completely, and make sure to keep airfield closed...
BOMBARD
There should be no mines. The only danger is organic artillery (12*105mm, and some 75mm guns, and 81mm mortars), so...
Detach all heavy ships from nearby fleets (including KB), and bombard. If there are heavy ships you can go point-blank. If you want to get little risk, use also Destroyers at point-blank. Actually Christmas Island should be big enough to rearm those Destroyers main guns.
Now, when KB is done hunting remnants, unleash full complement onto Palmyra. There are no AA defence anyway, so maybe strafing? Does squads, or artillery have any buildup AA capability?
In few days, Palmyra will use ALL supply because of bombardments, and defenders should have most squads disabled, because of it. So in short time, there will be unsupplied Marine Division, with most squads disabled, and with gigantic Fatigue, and Disruption. So why actually waiting with counter-invasion? Get those Divisions onboard immediately. KB will rearm, and while it will be back, it should accompany invasion fleet. Remember of constant bombardments (mostly unopposed). Land just ONE DIVISION, it should be enough. If not, exchange it for other. You only need to take LOTS of supplies. In two-three weeks, there will be 10k new workers at River Kwai bridge
