This has been helpful for me to understand the mechanics (I now better understand how the charge flank dynamics carry over into subsequent fighting phases) - so if you would be so kind, I wonder how this should optimally work out for the billmen? Bear with me as I have been trying to learn the game by myself. Let billmen1 be the UG charged by the knights and billmen2 be the neighbouring UG.

If billmen1 align to the charging knights (SP2.7), billmen2 would remain in position, out of contact and support, and would have to prompted move into an overlap contact corner to corner or side edge position in the movement phase to provide support in the fighting phase. In a subsequent move, billmen2 from overlap could wheel or turn to gain +2 flank bonus on the knights in a subsequent fighting phase (per p 132).

If billmen1 do not align the the charging knights, billmen2 would provide overlap support in the ensuing fighting phase if they do not move. Alternately, could billmen2 prompted move into a position to flank charge in the following charge phase by moving their front edge to a position past the front edge of the knights (assuming they did not start their move in the close proximity zone of the knights - which begs another unrelated question - is the close prox zone 1BW in pacto or is it 1/2BW)?

In either case, what have I missed, and how would an experienced billmen player play this out? As an ex-DBA player, my instinct would be the first option to align to the charge, move the support to overlap then move to "shut the door" in the second turn.   

Thanks everyone for your time and patience - and I apologize if this reply sidetracks the thread.

I would have also thought the second billmen unit would get the flank modifier in the fighting phase (but not in charge combat) imagining that it wheeled and charged the side edge of the knights in the charge phase.