No units use any missiles when set to Guard Commander. They will struggle to get adjacent to their commander every turn, melee attacking anything adjacent to them (if there is something).
Otherwise, as said, all you can do is set the units further back, so they have to advance before firing. Of course, this complicates buffing (no guys, wait for Strength of Giants, THEN rush forward and throw Javelins!), and is somewhat less effective if you don't have other shielded blockers to maintain a front line for those skirmishers.
What I'd love, is a somewhat more interactive tactical display, so even though it's scripted, you could lay out an actual game plan, sort of like a sports play. Little paths and arrows for each squad, so hopefully they go where you really wanted them.
Oh well.
