@ncscswitch:
IF you are not faced with a KJF by the United States, there is a small advantage in number of units sent toward Moscow in the first 3 turns of the game by purchasing an IC on J1.
It is not a huge advantage, but it is significant. The J1 IC is, like many other early moves, a gamble. And the success or failure of it is contingent upon the reaction (if any) to the build.
Whether you purchase an industrial complex on a 3 IPC territory on J1, or produce 2 transports, that investment still doesn’t see Japanese ground units into Asia until J2.
On J2, units at an industrial complex are forced to appear where the industrial complex is. Units loaded onto transports have a much greater range.
And at any rate, on J2, the 15 IPC industrial complex will get you THREE units into Asia. The 16 IPC transport buy will get you FOUR units into Asia.
What NCSSwitch is probably thinking is that an industrial complex in French Indochina lets you set up a quicker “feed” into India. That is - two transports moving from Japan to French Indochina can drop 4 units, but on the next turn, those two transports must return to Japan (so will have to drop units at Burytia or Kwangtung next turn). If the transports alternate pickups, that’s two units a turn reinforced into French Indochina (and two units a turn into the Burytia or Kwangtung front). On the other hand, three units produced at French Indochina at an industrial complex is three units.