Good point, that Special Forces are the ones using that deception tactic. It is reported though, that some regulars get a taste of firing AK’s in combat training. I can’t say why. I hasten to add that I have no direct knowledge here beyond what I read.
When I was at Ft. Ord we did OpFor training, dressing up in Russian uniforms, using Soviet vehicles and weapons. What was impressed on use about the AK 47 was how crude the thing was. It and the ammunition were also heavier than ours. I don’t like carrying heavy stuff.