Seow Buay came up with a compelling argument for an aggressive first turn strategy for the Japanese. Basically, the idea is to launch an amphibious landing on Turn 1 with 2 regiments. My argument is using assault table, there is no chance that the amphibious assualt can fail.
In the previous games of Singapore that some of us tried, the Japanese player adopted the historical strategy ie drive down the W Coast from Jitra, supported by an amphibious assault on the E Coast against Kota Bahru. Other landings (mostly against Kuantan) were made later, usually with reinforcements arriving in T5. This stragegy did not work because the narrow coast strip on the W Coast and the single railroad track from Kota Bahru could be blocked easily. The later Kuantan landing was also ineffective, because by that time the British player would have had time to set up a strong defence just West of Kuantan.
An alternative strategy is to make a landing at Kuantan on Turn 1 with two infantry regiments. The British player is unlikely to intercept this landing (see below **). There is a 2/3 chance that the landing will succeed, in which case the Japanese player would be able to advance to the central railway track and start moving south to Singapore as well as threaten to cut the supply of all British units further north. At the same time, remaining Japanese units (2 infantry regiments and 1 armour unit) move against Jitra for the drive down the W Coast.
There is however a 1/3 chance that the amphibious assault will fail in which case one infantry regiment is lost and the other comes back on T2. In such a case I think the outlook for the Japanese is quite bleak as the next attempt against Kuantan would have to wait till Turn 3 (given the time needed to gather forces in the embarkation ports) and by that time a credible defence would have been formed West of Kuantan.
Overall this strategy gives the Japanese player a 2/3 chance of a good result, as a successful T1 Kuantan landing will usually result in a draw to a substantive victory.
** What if the British player intercepts the Kuantan landing with Force Z. In this case, the 1st landing regiment is likely to be repulsed. But Force Z can only be used once per turn and hence the Japanese player can immediately divert the 2nd Inf regiment originally slated for Kuantan plus his remaining other 2 infantry regiments to Mersing for a second amphibious assault. In this case the Japanese player gives up the land assault in the north.