The translator of this discourse, Paule Ive, attributes the original French work to William de Bellay. Everyone else seems to attribute it to Raimond Fourquevaux. According to Wikipedia the original was published 1548. This translation dates 1589.
The Harquebusse hath bin inuented within these fewe yeares, and is verie good, so that it be used by those that haue skill, but at this present euery man will be a Harquebusier : I knowe not whether it be to take the more wages, or to be the lighter laden, or to fight the further off, wherein there must be an order taken, to appoint fewer Harquebusiers, and those that are good, then many that are worth nothing : for this negligence is cause that in a skirmish wherein tenne thousand Harquebussados are shot, there dieth not so mutch as one man, for the Harquebusiers content themselues with making of a noyse, and so shoote at all aduentures… Amongst other weapons least accustomed, are the Bowe and Crossebowe, which are two weapons that may do very good seruice against unarmed men, or those that are ill armed, specially in we weather, when the Harquebusier loseth his season. And were it so that the archers and crossebow men could carry about them their prouision for their bowes and crossebowes, as easily as the Harquebusiers may do theirs for their Harquebusse, as well for their readinesse in shooting, as also for the surenesse of their shot, which is almost neuer in vayne. And although the Harquebusier may shoote further, notwithstanding the Archer and Crossebow man will kill a C. or CC. pases off, aswell as the best Harquebusier : and sometime the harnesse, except it be the better, can not hold out : at the uttermost the remedy is that they should be brought as neere before they do shoote as possibly they may, and if it were so handled, there would be more slaine by their shot, then by twice as many harquebusiers, and this I will prooue by one Crossebow man that was in Thurin, when as the Lord Marshall of Annibault was Gouernour there, who, as I haue understood, in fiue or sixe skirmishes, did kill and hurt more of our enemyes, then fiue or skixe of the best harquebusiers did, during the whole time of the siege. I hauve heard say of one other only that was in the army that the King had under the charge of Mounsieur de Lautrec, who slewe in the battaile of Bycorque a Spanish Captaine called Iohn of Cardone, in the lifting up of his helmet. I haue spoken of these two specially, because that being employed amongst great store of Harquebusiers, they made themselues to be so knowne, that they deserued to be spoken of: what would a great number of sutch do…
The Harquebusse likewise must be accompted amongst weapons, and the Bowe and Crossebowe also. True it is that I would that these two last should be caried by the people of the Countrey where they haue their most course, and but a certaine number of them.
…the Harquebusiers, Archers, and crossebowmen should be armed with a shirt [with] sleeues of male, and with a good headpeece : or for want of a shirt of male, they should have cotes of plate, and good Jacks, yet they are almost out of season, but that maketh no matter, so there be any aduantage to be found by them.
[Fourquevaux describes a method for organizing the troops into a Legion of 6100, divided into 12 bands, each further subdivided into six companies of four squadrons of two deciniers. Ten of the bands would consist mainly of pikemen, with 1/12th of the band being shot. Fourquevaux recommends that half of this shot be archers and crossbowmen. The remaining two bands, called the Forlorne Hope, would be mostly arquebusiers with a few pikes in loose order and some archers mingled among them.]
…Those of the sixt Corporall shalbe the one halfe pikemen, with the other halfe Harquebussiers, except that we would mingle some Archers amongst them, and make that the one chiefe of squadron should haue all his men to be Harquebusiers, and that the other chiefe of squadron should haue one Decene of his men to be all Archers, and the other Decene to be all Crossebowes, to the intent to haue seruice of these people, in places where the Harquebusiers should be unseruicable, as in the rayne, as is aforesaid, or to make any secret charge where the fire might discouer them, or in any other place where these two weapopns might serue more sure then the Haquebusse… [Of the Forlorne Hope] Foure of these corporals shall haue all their men Harquebusiers, which may be mingled with Archers and Crossebowes who so would.