It was recommended that if your cavalry was weak, then it should be stiffened with light armed foot soldiers. Vegetius also stresses the need for adequate reserves to prevent an army from enveloping one's own or fending off cavalry from attacking the rear of the infantry. Alternatively, they could perform an eveloping manuever on the opponent. The positions taken by the commander was usually on the right wing.
"Roman Army Tactics." The Roman Empire. Web. 23 Mar. 2010. http://www.roman-empire.net/army/tactics.html.
Envelope. Digital image. Wikimedia Commons. Web. 23 Mar. 2010. http://upload.wikimedia.org/wikipedia/commons/7/7f/Envelope_-_Boonville_Address-000.jpg.
