Here are some ideas for voice commands I think are better than the current and the OP:
'Form shield-wall!'
'Steady, lads! Steady!'
'Shield's up and advance!'
'Shield's up and flank left!' (right too)
'Stick together!'
'We're beating them!'
'They run from us!'
'Fall back slowly!'
'Defend our archers!'
'Take cover!'
'Incoming cavalry!'
'Attack their cavalry!' (and infantry, archers, etc.)
'Cavalry, regroup on leader!' (and infantry, archers, etc.)
'Cavalry, charge their archers!' (and infantry, cavalry, etc.)
edit:
BTW if just the people in my battalion could see my voice text, that would be nice.