Mishnayot Tamid 6:3 says that the kohen who wins the right to offer the daily incense brings a buddy with him to hold one of the vessels and help him retrieve any dropped incense:
מִי שֶׁזָּכָה בַקְּטֹרֶת, הָיָה נוֹטֵל אֶת הַבָּזָךְ מִתּוֹךְ הַכַּף וְנוֹתְנוֹ לְאוֹהֲבוֹ אוֹ לִקְרוֹבוֹ. נִתְפַּזֵּר מִמֶּנּוּ לְתוֹכוֹ, נוֹתְנוֹ לוֹ בְחָפְנָיו
The one who had won the right to the incense took the censer from the spoon and gave it to his friend or his relative. If some of it spilled into the spoon, he would give it to him and put it into his hands.
Why does the Mishna specify that the assistant is the offerer's friend or relative? Is there particular practical or symbolic significance to there being a prior relationship between these two kohanim?