Weird things happen when you combine and split units:
Split units out of a division, and it looks like some of their elements take on generic names? (I'm not sure about this, but I was noticing a number of "infantry" elements after splitting out a division).
I'm also scratching my head at the 1st WV Brigade, which now contains the 16th and the 18th New York regiments... Does a division repopulate its names when it divides?
Also, odd issues and undocumented features with the split behavior:
1) I notice that the Irish Brigade can be split as if it were a division.
2) Sometimes a division must be split a number of times to reveal all its components. (it seems this is particularly an issue when a leader is attached).
Combination: Militia units from two states can be combined into one militia unit. Interesting.
1) More interesting: the combined unit will adopt one of its states as the correct one. e.g. combine a PA and a WV militia unit of one element each -- it becomes a PA militia unit of two elements.
2) In the above situation the elements take on the PA identity as well, so that the 2.PA Volunteer element and the 5.WV volunteer will both have the "PA" icon in the element panel.
It's not clear what's going on under the hood -- in this case, does the 5.WV volunteer lose its combat bonus for being in West Virginia?