Historically it took about 40 days to Hannibal´s army to move from the Rhone valley to Taurasia (modern Torino). In the game, units with hvy inf movement make it in 18 days. Now, Livy wrote that Hasdrubal crossed the Alps some years later at a much faster pace, the reason for Hannibal´s delay was that he had to fight several hostile tribes that later became friendly, presenting no problems to Hasdrubal later.
So, my question is, if I put some units in ambush mode in the Alps regions, would they delay hannibal´s passing army, like historically? and related to that, how do you pùt a unit in ambush posture from the start?