So I too had some questions on this, as there is no way to see the effect commanders have directly on troops like there was in vb6.
In vb6, if you assigned a guy with ground combat %, then you could immediately see the strength of the unit update.
There's not really any way to verify this in C#. Offense gives hit chance. Defense gives the inverse through fortification, but doesn't show anywhere, it's just a hidden modifier in combat.
So on and so forth for artillery and the rest, there is no way to see the direct effect of any officer.
Except through training; Training % will let you get to a Morale of 100+(5*%). A training bonus of 10% lets you get to 150 morale.
So I tested, I put a 10% Training officer with sufficient capacity on my lowest level unit.
I put a 20% training officer as the parent.
Everyone had enough HQ And Command rating to facilitate their own stack, and attached stacks.
But my lower formation still capped at 150 morale.
So if higher formations aren't providing ANY bonus, what is their purpose?