[Mobhack]

As well a giving them a small reaction turn - also try giving the platoon HQ a path to follow that takes them into where you think contact will occur.

If you want a general advance of the defending AI - then you can use neutral or attacker-held Victory hex(es) out in attacker land. See the tutorial scenario, as that is the method used to tempt the Iraqi defender into giving up his defensive positions and kamikaze charging headlong into the USA trainee there.

However, V-hexes on the attacker's side are
a) a clue to the human player that the AI will come at him (which he can then exploit) and
b) a pain to get right (setting appropriate reaction turns for all defenders, and the fact the AI will sometimes decide to step off and regain them early).