I've never understood the concept of carrying the fire steel on the knife sheath....It's not like you have to quick draw it like you would the knife itself...you still have to prepare for the fire, gather stuff to burn, etc...plenty time to reach into your pocket, pack, pouch, whatever, to reach for the fire steel...or your Bic...firesteel on the sheath, just something else to get snagged on something along the way...
I carry matches in my first-aid kit....works pretty good.