This post discusses the rules linked here.
I am going to try following the list of chapters that is used by Charge! So the first chapter discusses the organisation of units, their formations, and how this determines their movement rates. This part is uncomplicated: the organisations used by both Charge! and The Wargame require little alteration.
The biggest change from Charge! rules is to use four twelve man companies instead of three sixteen man. On aesthetic grounds alone, I prefer the 'square' organisation, and I suspect that Charge! adopted sixteen men per company solely because it uses firing groups of eight men. But my musketry will use a system based on The Wargame and that uses six man firing groups, so the twelve man company will work well enough.
Light infantry are organised as per Charge! The use of open order formation is one instance where hexes are beneficial: it is easier to denote use of open order by limiting deployment to four figures per hex rather than having to carefully maintain proper spacing between every figure.
The cavalry squadron organisation of eight troopers plus an officer is nominally as per Charge! but in reality represents a slightly weaker unit as my officers are nothing but eye candy whereas in Charge! officers would fight along with the rest of the squadron. Cavalry don't fit so well into hexes. A squadron must be able to opt between deploying in a single line or a double line: in the former case the space required dictates that the squadron can use two adjacent hexes.
The next step will be to lay down the various movement rates. There are some problems here, but also some benefits from using hexes: but this will be covered in the next post.
I put a lot of photos into the section: they aren't particularly informative, but do give some feel for what the units will look like when conforming to hexagonal terrain. The formations in column do not look pretty: the half hex offset between hex rows is aesthetically unpleasing. So the photos in this case do serve to warn about how the look of the wargame suffers in this manner.