Hi Robert
I'm trying to interpret Henri's cuirassiers in the context of DBA-RRR more than DBR, as the former is a simpler system much closer to DBA.
Secondly, this tactical innovation which actually began decades earlier but was refined by Henri (and I can give you pages all about that) had nothing to do with the terrain features of one particular battlefield (Coutras) and everything to do with a host of other factors (which I won't go into here but they are covered in detail in the article by Love).
Here are a few excerpts from the article for you to do with the use and effect of Henri's cuirassiers against enemy knights. It's missing the footnotes to quotes and the enormous number of references to mostly contemporary accounts, but without sending you the article (which I can do if you wish, as it's a very well researched study worth reading) it's a start. I've included the separate paragraph from John A Lynn's article that Love takes issue with as well. There's a LOT more than this, but it sets the tone.
'Henri trained his men to form compact squadrons six or seven deep and to charge with the sword, dispensing with the unwieldy lance and using pistols only in the ensuing melee.'
'What was unique to Henri was the way in which he organised and trained his squadrons in practice, combining the strength, weight, and maneuverability of the
Reiter-style formation of three hundred to six hundred men with the speed and shock value of the heavily armoured lancer, teaching them to charge home at the gallop with the sword alone. (There is no evidence to support John A. Lynn's contention that at Coutras and Ivry Henri's cavalry "used their firearms for an initial shot" before charging with the sword. The "initial shot" was fired by arquebusiers placed in the intervals between the various squadrons of horse.)'
John A. Lynn, Tactical Evolution in the French Army 1560-1660, p.183: "By Temperament and professional conviction, Henri could not accept the sterile
caracole. He reshaped French cavalry formations and tactics, reducing the depth of squadrons to six ranks, and even to five. At Coutras (1587) and Ivry (1590) his cavalry used their firearms for an initial shot, but then charged home with the sword at the gallop. In accord with the counsel of la Noue, Henri demonstrated that in shock attack the six-rank formation was superior to cavalry drawn up
en haie, as the royalists were at Coutras. To bolster his cavalry, Henri also interspersed companies of musketeers between his squadrons, a practice that continued throughout the Thirty Years' War."
'This was a stunningly successful combination. It not only enabled the king's cavalry to punch through the extended lines of enemy lancers, but also to receive the shock of the latter's attacks "with a firm encounter and continued [good] order". Moreover, the new formations were remarkably flexible in combat, being easily adapted as the situation demanded. At Ivry in 1590 the king ordered his cavaliers to maintain their ranks in the charge to achieve the greatest effect against the League cavalry's uneven and disorderly lines. But at Amiens in 1597 he instructed his horse to "leave a good space between one another, which having been done, they found that the shock of the Lances [of the Spanish relief cavalry] not meeting a firm opposition proved for the most part in vain..." Thus trained and reorganised, Henri's
gens d'armes - described by one contemporary as "men of despair, enclosed in their cuirasses like turtles, enemies of ease and repose" - were unbeatable.'
'Although Henri had used his new cavalry formation as early as 1586, it was not until the battle of Coutras, a year later, that he first demonstrated its full effectiveness in combat. Having divided his thirteen hundred cavalry into four squadrons - "united and compacted in firm perfect array" - he patiently awaited the enemy lancers' disorderly attack
en haie until it had almost reached his position where, winded and losing momentum, it was met by concentrated fire by Huguenot infantry and artillery. Henri then led his own
gens d'armes forward at the walk, the trot, and finally the gallop, shattering the royal cavalry's thin extended lines "with the first shock". Two years later, at Arques in September 1589, Henri proved again the effectiveness of his compact cavalry squadrons where his
gens d'armes - supported by infantry and artillery fire - attacked the Catholic League's near overwhelming forces "with a tenacity that the king alone could inspire," winning him another stunning victory.'
'If, however, any doubts remained over the superiority of Henri's mounted formations or tactics, these were swept away at the battle of Ivry where he smashed the army of the League. On a field chosen by the king because it was suited perfectly to the movements of cavalry, he deployed his 2,500
gens d'armes as usual into seven squadrons, five ranks deep, that were all "glittering with yron and steele..." He also order the 250
Reiters in his pay to dispense with the
caracole tactic and charge home with the rest of his cavalry. This was significant, for when performing their customary maneuver the
Reiters always wheeled to the left after discharging their pistols. But the danger here was that they often collided with other oncoming friendly cavalry, throwing the latter's attack into disorder and blunting its effect. Indeed...after performing the
caracole, the League's
Reiters did collide with the long lines of charging League lancers, destroying their momentum and rendering their weapons useless. At precisely that moment, Henri crashed through the enemy's lines with his own squadrons of cavalry, rallying his troops and then crashing though them a second time. What followed was the quick liquefaction of the League cavalry into rout as it streamed off the field, abandoning the infantry to the triumphant king.'
...
In DBA-RRR I'm not convinced you can adequately reproduce this with the rules as written. 2-deep Pi charging forward to meet a wider line of charging Kn results in roughly equal factors, Knights on 4 and Pi on 5 with rear support but potentially -1 from an overlapping element of Knights (assuming Kn and Pi have equal numbers, 2-deep vs 2-wide), but with the Knights having a QK. So it's more likely that it will be the Knights who will punch a hole through the Pi, taking both elements in one hit. Even if the overlapping Knight element has been recoiled as a result of shooting by Shot or Dragoons friendly to the Pistols, it's still Pi at 5 with no QK vs Kn at 4 with a QK. Again my money is on the Knights.
The closest to reproducing the results of Henri's battles against Knights with his Pistols in DBA-RRR is either to allow the enemy line to meet his own line of Pi interspersed with Sh/Dr, or to advance his own line of Pi interspersed with Sh/Dr into that of the enemy, keeping side-support intact in order to penalise enemy mounted with a -1 (mounted fighting Pi who are flanked by Sh or Dr) and also improve the odds of his own Shot (but not Dragoons) (+1 if Sh fighting mounted if flanked by Pi). But if he elects to let his Sh/Dr shoot at the advancing Knights and then charge out with his Pistols, he loses this side support. Perhaps DBA-RRR insists on modelling the mutual side support of Pistols with Shot/Dragoons only by keeping their line intact, in which case the charge of Henri's cuirassiers at the trot and finally the gallop doesn't occur on the table ahead of the line of his shooting support troops. Because, if he does charge his Pistols forward of his original line - leaving the Sh/Dr even slightly behind - he forfeits their close combat side-support in the game. He then relies purely on the results of their shooting in the shooting phase. And again, if he charges forward against the Knights, he is at a disadvantage to the QK of the Knights with a similar or equal CF.
A potential solution to this, which would allow Henri's Pistols to charge forward of his lines of supporting shooters - preferably after they have fired at least once at the enemy - and be able to hit the opposing Knights with the shock force that they historically possessed would be this: *Pistols with rear support QK Knights*
Pistols with rear support QK Knights.
That's all you would need to allow Henri's cuirassiers to have an even or slightly better than even chance of defeating enemy Knights,
equivalent to what they already have against him, allowing him to charge forward of his lines of supporting arquebusiers. And remember,
Henri still needs to go 2-deep to achieve this, thus narrowing his frontage. Also remember that earlier 'Pistols' shooting in deep
caracole fashion against the enemy are classed as Cavalry and not Pistols in DBA-RRR, so there is no unhistorical retrograde flow-on effect from introducing this modification. This QK would only apply against Kn and not other mounted because other mounted have options and behaviours available to them to offset it.
Without 'Pistols with rear support QK Knights', Henri must keep his lines intact to claim the much needed close combat side-support benefits...and we then 'imagine' that his cuirassiers have charged forward to meet the enemy, even though on the tabletop this doesn't physically occur.
It probably comes down to how DBA-RRR is modelling the combat in the most top-down abstract fashion. i.e. there are things occurring that are simply not shown with elements on the tabletop.
'Pistols with rear support QK Knights' adds a dimension to the game that reflects the historical record *without* needing to pretend there are things occurring that aren't physically happening on the tabletop battlefield. And I don't believe that by including it, it makes the side-support mentioned above redundant. Both should work in their own time and place as battlefield options arise and permit.
Cheers