I'm playing the Great Plains scenario.
Hasdrubal Gisco is the Carthaginian OC. He trumps a Roman leader and activates. He's too far from a line of Heavy Infantry to issue a line command so he uses his Orders capacity to order part of the line forward. Himilco is stacked with one of the HI units.
Can Himilco move with the HI even though he's not active?
The HI units move forward. Because they moved to contact with the enemy they have to Shock attack.
Himilco's Charisma is zero, but if was higher than that could Himilco influence the combat die-roll even though he's not active?
If Himilco was able to move even though he was not active, can he activate normally later in the turn?
I think yes, he could move with the HI unit, yes he could influence the combat, but I don't know whether he could activate later in the turn.
yes, yes, ? ,depends if he's in an EZOC. If he isn't, then yes. If he is, OC could move him out, or could be freed by combat. You can decline to use him if its his turn to be activated, or use him to shock units in his command radius. If you defer to use him, and later he's freed from the EZOC he must be the first "next" to be activated outside of momentum/trumping. See Leader Activation rules.