I've recently found myself drawn back into playing H&M (Vol I), taking the opportunity to visit some of the scenarios that I had previously not bothered much with. I'm using just the basic rules at present in order to get back up to speed with it, and it all flows along very nicely with out much recourse of having to consult the rules.
The system is actually quite clever in the way that it can encompass battles of many sizes using only one map plus the overlays through the use of slightly different CRT's and movement rates, etc. Thus we have 'small, normal and grand' battles. Obviously, we do accept some abstractions here, so don't look for ground scales of detailed unit sizes. We can assume that unit represent bodies of troop that range from a few battalions to a few regiments. In any case, unit size is represented by a morale number rather that a number which represents the number of troops, and this works well within the game context.
The first of the many optional rules are those for formation and facing, and whilst these do add some 'realism' into the game without much additional complexity, they do add a little to playing time. When combat occurs, we cross reference the stance of the attacking unit with that of the defender to yield a possible DRM.
there isn't a handy PAC to cover this, you must instead glean what you want from the rules, although strangely, there is one with the Vassal mod. I therefore decided a while ago to produce one, which I did, and made it available on the games BBG page, and to prove it, here is the link;
https://boardgamegeek.com/filepage/191669/formation-modifiersNow, this got me thinking about how relevant this is given what the unit counters represent. I did consider if that within such an obviously large body of troop, they (the sub-units) would not all be assuming the same frontage or formation. I'm thinking of things such as refused flanks, and reserves in column and so on.
OK, they are after all just optional rules, the whole point being that you use them or not at your discretion, but I thought it would be interesting to see what other players think.