I don't know if it's true, but I've heard a couple of times that there's only one factory in the world that manufactures ferrocerium rods in sizes bigger than lighter flints, so the only real differences are handles, coatings, lanyards and strikers.
That's really interesting. I can say of my Doan, Coghlans and Military Match ferro rods, that they all certainly "seem" the same but I have no way to be sure unfortunatly. At one time I found a bucnh of Coghlans magneseum brick fire starters dirt cheap so I bought a bunch and removed the ferro rods then threw away the mag blocks. These are sort-of my standard by which I compare all of the others, since these ferro rods are the ones that are compact enough that I actually EDC them.