If you want to discharge someone else's obligation the question would be if they are ברכת הנהנין - brachos on pleasure - which one cannot repeat if he already fulfilled his own obligation, or if they are ברכת השבח brachos of praise, which can be repeated to fullfill other's obligation.
See: Pri megadim (Aishel Avraham 46/14) who writes that by some of the brichos ha'shachar one cannot repeat them for others, since they are - ברכות הנהנין - on pleasures, and sefer Ishei Yisroel 5/(footnote 3).
However, if they are being repeated for the sake of shul decorum, [in my opinion] it would be halachiclly unnecessary and a bracha l'vatala - in vain. This should not be compared to Chazoras Ha'Shats which was instituted by chaza"l even if no one actually needs to fulfill their obligation.