Scourge of War Boards

I had a Union brigade in line facing east between the York and Hanover Pikes just east of Gettysburg. When I ordered the brigade to the Lady farm on the Hanover Pike east of the brigade's location, the three right regiments went with the brigade commander to the Hanover Pike and headed east toward the Lady farm. The left two regiments went to the York Pike and went west toward Gettysburg until they hit the Hanover Pike and then took the Hanover Pike east to the Lady farm.

Is it normal for the game to break up a brigade based on the closest roads the individual regiments can use, or should the road to be used be based on the location of the brigade commander so the brigade stays intact? On the other hand, if the brigade commander is somewhere else on the map, you don't want the regiments to choose the roads to use based on the most convenient road for the commander who may be distant from the regiments.

Maybe I just answered my own question.

Also, I noticed the Union brigade commander rode through the Confederate battle line uninjured (without his troops) to get to the objective location which was just behind the Confederate line.

You did answer your question. It is based on the regiments location. Kind of strange for the brigade to split up like that, but I suppose it could happen.

Most of the time commanders will be killed if they move close to an enemy regiment, but not all of the time. There is a random factor there.