 Two or more of these battalions were to form the regiment, which was thus theoretically 1,100 men or stronger, but unlike the tercio, the regiment had the battalions as fully functional sub-units, each of mixed pike and shot which could, and generally did, operate independently, or could support each other closely.These battalions were fielded much less deep than the infantry squares of the Spanish, the pikemen being generally described as five to ten ranks deep, the shot eight to twelve ranks.In this way, fewer musketeers were left inactive in the rear of the formation, as was the case with tercios which deployed in a bastioned-square.