Re-reading The Gun By C.J. Chivers which is an interesting book. There's some really good information about the design and development teams. The opinion of the writer with supporting evidence is that the story of Kalashnikov, an army Sargeant being the "designer" of the AK-47 is mostly propaganda. Kind of a perfect class struggle success story, the humble sergeant beating out the well educated engineers.
During the design process, periodically they would all meet up for "competitions" to see where everyone was at in their designs. Design teams were encouraged to incorporate advantageous design features they saw on the arms of competing teams. Chivers uses this as an example of how a nation builds a rifle, and the M16 as an example of a rifle design accepted somewhat by default.
But one very interesting thing that was mentioned in the book was the fact that Hugo Schmeisser was held as a prisoner of war in Izhevsk where the design teams were working. I tend to think it's highly unlikely that they didn't involve Schmeisser at some point during the process. The AK-47 is very similar in appearance to the Schmeisser designed Mp-44, with additional influence obviously from the Garand (rotating bolt, long gas piston, clearly the fire control group).
I've had the opportunity to handle, disassemble and fire the Mp-44 and I have to say I was very favorably impressed, it was a very well thought out weapon.