The more I look at it, The less I like our position - we are deployed in the middle of a wood with some height advantage but we don't have fields of fire. Also the Rebels do not have to attack us - we do not dominate the road to Springfield for example. The position to the SW of Gibson's mill was much better.
However, making the best of a bad position, I think all should build defences so then all can sleep so A All our forces will be needed from daylight, so the reserve is likely to be our cavalry as opposed to an infantry brigade.
As for HQ and Hospital, I go along with Franc.