Arrival of the Mexican army at the Alamo

Stirring scenes with a great score - was this filmed by John Ford?
According to this page on the Alamo
Director John Ford showed up on the set, and let John Wayne know that he wanted to direct some of the picture. Wayne sent him out with a small crew to do some second-unit work, mostly of Mexican cavalry riding through the countryside as they approached the Alamo, and Frankie Avalon estimated that the footage filmed by Ford made up approximately 10%-15% of the finished film. Other sources, however, have said that Wayne eventually deemed most of Ford's footage unusable, and little if any of it made it into the final cut of the film. According to these sources, the footage that Ford believed he shot of the Mexican cavalry patrolling the countryside was actually re-shot by a second-unit director, although Wayne didn't have the heart to tell Ford.