I am not a lawyer, but if one was going to bring the assaults in as being part of a criminal gang I would think that statement would be part of the assault description. It is an interesting difference between the murder and assault statutes. I could easily see an assault law include being held accountable for the assaults committed by accomplices during another crime.
It's part of the Organized Crime statute, which points to the assault statute. Assault is a crime either way, but the "gang" statute says commission of certain specified underlying crimes as part of a gang, enhances the penalty associated with the underlying crime.
The "aid / abet / accomplice" statute is similar to the organized crime statute in that the underlying conduct must first be a crime, in order to apply the "aid / abet" widget.
The legal fiction worked by the "aid / abet" statute is that a person who aids or abets, actually committed the crime. There is no distinction between doing the crime, and helping somebody else do it.