The Templars were led by a Grand Master, and their charter specified he must be Frenchman. A Marshall led all the military forces, and each city or province had its own Commander. The Commander of Jerusalem was the most important of these, and that position was often a stepping stone to Grand Master.
Knights and sergeants filled out the fighting forces, but, as today, the actual fighters were outnumbered by their support troops. Many Templars were not fighting men, but merchants, tradesmen, and bankers.
In The Templar Concordat, we see the present day Grand Master and Marshall. Callahan and Marie would both be knights, although that term is no longer used.