You missed an important detail. The cross of equal length (not crucifix) is an ancient pagan symbol going back to like 10,000BC.
http://en.wikipedia.org/wiki/File:CROSS_Sacral_Stavros_from_the_Temple_Repositories_of_Knossos_1600_BCE_Heraclion_Museum_Greece.JPG
It's a symbol of good luck similar to the four leafed clover.
You know Roman Emperor Constantine I put this symbol on military wear. A pagan lucky symbol. And when they won, he decided to convert Rome to Christianity.