FTF, the Quarter Horse was a blending of different "breeds" of primarily spanish descent ( Andalucion, Barb, and Arab) that met the 16th century english horses turning them from the spanish stock horse, into a more sporting short distance race horse due to the English fetish of racing. It is NOT a one sided "race horse" turned stock horse. So you chose to focus on the TB influence of the QH, great, fine and dandy, but do not ignore the other side of what made the Quarter Horse.