Dsimounting units

[Aryaman]

Hi
I see there is an S to the side of some units in the DAG army generator, for instance Gascon ment at arms, when I press the S simbol I see the unit change from mounted to dismounted, but I can select it, so that when I select the unit for the army, then in battle I can´t dismount those Gascon men at arms, am I doing something wrong?

[Blathergut]

When you start the game, at deployment time, you right click on the unit and an 'alternate' button pops up. Click and you dismount. Only in deployment phase..not after.