Japan, like Italy, suffers from a huge ressource shortage, even at their starting IC level. This can be compensated to some point by buying from USA or SOV, but once these two are at war, your trade will probably collapse.
Imo neither ITA nor JAP benefits from an early IC build. Their practice is very low, their ressources too limited, a lucrative war too near for doing large IC builds. Better invest in additional units, thanks to practice it will become useful during the later days.
The true IC whores are USA and SOV, simply because they have high IC at the beginning of the game, tons of excess ressources and probably won't enter war before 1941.
As GER, I usually use a hybrid strat in HoI3: I build ~25 factories during 1936-1938, but add a few tanks, ART, planes and some CVL. The practice from LARM and ART comes handy to increase my army in 1938/1939, while INT is useful for some CAS and the CAG for my CVL.