CoE III

[Strider]

Leaders do have passive abilities that affect all of the units under them.
I prefer playing 'fighter' type units, so I do use mages as support units in my armies instead of as 'leaders', tho they can be used as leaders.
For now, at least, all Defenders do go first.
You do buy units in groups. A few are single purchases. They are then 'individuals' that you can place under a leader.