Hit the I key a few times to keep the messages on the screen longer. I've noticed that they'll repeat sometimes, although a message from 4 hours ago is no longer useful.
I haven't seen any effect from the Rally Troops button. Does it really help?
There's no problem passing one corps through another, at least that I've noticed. Look at the 3D view to see how much empty space there is in a line of troops.
You can see what a given corps command's order delay will be at the bottom of his unit card. This varies by distance, competence of the corps commander, and probably the need to translate orders. You can see this number change as you move the HQ around.
I get plenty of disarray when there's no other corps around to complicate things. Normally, when there are no enemy troops in the way, the corps keeps a good formation.
Today I gave one corps orders to advance to the other side of the map. Another corps got orders to link on his right. A third got orders to link in support, behind the first. A fourth got orders to link in support of the third corps.
Things went smoothly except for the fact that the supporting corps were very close behind the corps they were supporting, until they met the enemy. At that point all three corps intermingled. Not quite what I had in mind. I thought the supporting corps would wait until the first corps got bogged down, then advance. The 3D view showed an incredible mass of troops, but everyone had room to fight. And there was plenty of artillery, thank goodness.
On another part of the battlefield there were two corps, one in support of the other. These guys did a great job of clearing the enemy in front of them, and didn't intermingle too much, although everyone was fighting on the front line.
Hook