Those were Indian elephants, not the much larger and more aggressive African, and they were used in small numbers - 20 or so. The main defence was to scare them

Those were Indian elephants, not the much larger and more aggressive African, and they were used in small numbers - 20 or so. The main defence was to scare them or to lure them into a bad position. I'm envisioning all elephants working together with discipline and coordination which would make it nearly impossible to stop them.