Quote Originally Posted by Papewaio
They do get unit experience though and this can be a useful thing to toughen up a potential general or a use for an otherwise useless family member... who makes a pretty tough regenerating cavalry.

I sometimes have a second general in an attacking stack (besieged defender is another story). I give the second general the job of defending the gold general and breaking the enemy where it is too risky to lose the commander.
And a second general doesn´t collect the "scarred" attributes as well, I believe. They´re the downside of having your family members fight, they might loose them a lot of influence.