As to the latter two signatures it looks like:
Wm B Taliaferro
Brig Genl

Wm F Nance, AAG
for Brig Gen'l Cmdg
{Nance was Capt. and AAG for Roswell S. Ripley}

For the first signature the page is folded up obscuring it and something is written over the top.
That is the place where the brigade commander, Alfred H. Colquitt, would have been in the chain.

George