Would say thirded; but I've got something to add. Make sure to have some decent medium/light cavalry (rather than heavy cavalry as those tire too quickly) to cover your troops while they march upwards.

Also be sure to include the usual array of fair/long range missile units: it's nice when you climb upwards; rest; and finally turn your initial disadvantage to your advantage... (Especially as those hills are outright impossible to stage a proper battle on; with the exception of an ambush perhaps...)