Assume the Southern Drive is largely (but not quite entirely) off. The raw numbers are pretty straightforward. Something about 325 Diahatsu and 185 Shohatsu available could carry a single-wave assault force of 33,000 troops, plus some dozens of the bigger landing craft. Over one million tons of shipping, allowing both a 70,000 man assault force with armor against Oahu in addition to 4 Midway- sized air base units and garrisons set up on the outlying islands. The divisions these could draw from would be 16th, 48th, 4th, 2nd, 7th, 53rd and 54th. The fleet – including the battleships and many cruisers and destroyers – would require about 350,000-400,000 tons of tanker/oiler supply (out of 645,000 tons available in total) to stay 6 weeks at sea. Nagumo would gets 9 carriers, (Hosho, Zuiho, Ryujo added to the original 6 KB) for a total of about 470 combat aircraft including 180 Zeros, (these would not be on Formosa because Luzon is being delayed). Also, the escort carrier Taiyo with another 20 Zeroes. Add to that 100 seaplanes and a hundred or more twin engine bombers ready to stage forward to captured fields from the Marshalls.
Um, no, there were 312, Daihatsu (14-meter type), 315 Shohatsu (10-meter type), and 60 Toku-Daihatsu (18 meter type) as of December 1941. Aira Takizawa told you that twelve years ago.
312 X 70 = 21,840
315 X 30 = 9,450
60 X 120 = 7,200
So all your problems are solved man! 38,490 Sekret Ninja SLNF...and some army dudes! You can conquer the world!
Hosho? 1st Fleet air cover? 25 knots? She can't even keep up with Kaga. 11 A5M4 and 8 B4Y1 aboard?
Rjujo? 29 knots at least, but 12 A5M4 and 14 B4Y1 aboard?
Zuiho? 1st Fleet Air cover? 28 knots at least, but 12 A5M4? At least she had 12 B5N.
Taiyo? 21 knots? She was completed 2 September, worked up through October and started loading aircraft to ferry to 11th Air Fleet on 10 November at Sasebo. A5M4 again, no Zeroes.
Zeros? From Formosa? You mean the Tainan Naval Air Group and 3d Naval Air Group of 21st Naval Air Flotilla? They have 107 A6M2/21.
Kido Butai had 126 A6M aboard. 11th Air Fleet had 132 (25 were in Indochina).
Only 469 A6M1, A6M2-11, and A6M2-21, A6M3-32, including sub-types, were completed by the end of October 1941, probably the latest production that might get in service...and that's probably being generous. That is also including 113 of the A6M3-32, whose short range was unsuitable for carrier operations. So there were 356 carrier-suitable aircraft...and the Kido Butai and 11th Air Fleet between them had 258 of those.
BTW, the IJN had 24 AO and 2 AOG in commission on 7 December 1941. Seven of them - not quite one-third - were required to support Kido Butai. Four others were with the Southern Force's Distant Cover Unit. One (teeny little 380 GRT Moji Maru) was with the South Seas Force. The AO had a combined displacement of 233,657 GRT.
Would it work? Not necessarily, but the basic numbers are there. It would probably all come down to whether Nagumo got surprise in the first attack or not. In the meantime the southern drive could have still cobbled together the occupation of Borneo, Mindanao and maybe even the Celebes in the meantime.
The "basic numbers" aren't there.
Except the Japanese assumed the conquest of the Dutch East Indies required Malaya and the Philippines as prerequisites.