For me, that's an interesting comparison because I don't own "Flick of the Switch" and probably haven't heard many of the songs.
Bedlam In Belgium The main rhythm track is out of tune, the band is pushing and pulling, and the sounds are on the "small" side. Disregarding Mutt Lange's tendency to lead bands into harmonies they might not have created on their own, etc., I'm pretty confident that he would have caught the basic problems with the track and never let them get out of the studio.
Guns For Hire Similar tuning issues, similar small sounds. Band seems a bit tighter. Sounds like a demo.
Nervous Shakedown Better drum sounds and performance. Closer to "Back In Black" than the other two, but still not in the same league.
Seems to me that AC/DC "needs" (or benefits from) a producer. or at least Mutt Lange's production. Or . . . ???