Ok, don't have the rules with me, just the February electronic version, which says:
"A March move must start further than 400p from all known enemy not light troops or beyond a friendly PF or TF. It ends early without PIP penalty 40p short of visible enemy other than Psiloi or at its closest approach to enemy who will shoot at it that bound."
This is clear, you cannot move into contact with visible enemy using a march move unless they are Psiloi. Hope this helps.
D.