Even making PIAT teams into 3 man squads would seem to make them better. Keep the double star. I think the 3rd man would be the one to make it out alive and possibly get a change later to fire the PIAT.
Really, this probably needs to be applied to all 2 man teams. Hoping this is addressed uniformly in the next patch though.
Yes, Two man teams (including flamethrowers and the like) really need help, even adding another 2 guys would be great.
2 Man recon teams should be left alone, however, since they serve a different purpose.