 Finally, its depth meant that it could run over shallower formations in a close assault – that is, should the slow moving tercio manage to strike the enemy line.Armies using the tercio generally intended to field them in brigades of at least three, with one tercio in the front and two behind, the rearward formations echeloned off on either side so that all three resembled a stepped pyramid.The word tercio means "a third" (that is, one third of the whole brigade).