Mostly fictional?
Like the first movie it seems to create a storyline out of whole cloth. While the martial arts sequences are decent other things, such as Japanese baby ninja spies and Japanese saber woman spies probably come straight out of the scriptwriters' noggin rather than anything real. Although it might have been hard to make an opium addict palatable as one source (wikipedia) said. On the other hand it might have made a better film.
A quick check came across this, http://www.kwokwingchun.co.uk/ip-man-biography which offers a biography different than that depicted in the films. Or can anyone cite evidence like a journal article "Pre-pubescent Infiltration and Subversion techniques of the Imperial Japanese Army"
LaoWombat