There seems to be some confusion about when the green cross was adopted by the Order of St Lazarus, some internet articles confidently state that it was not adopted until the 16th Century. However Savona-Ventura and Michael W Ross clearly allude to the fact that The Knights of St Lazarus at least were using the green cross on habit mantle and harness from 1314 at the latest – prescribed by Siegried of Flatte, Commander of Seedorf in that year.* Master Generals of the order were probably wearing some form of cross on their cloaks a little earlier at least – Thomas de Sainville (1277-1312) is depicted on his tomb originally at Boigny with a couped cross on his cloak at the left shoulder.
*The Heraldry and Development of the Order of Saint Lazarus of Jerusalem, The Journal of the Heraldry Society of Scotland No.36 Summer 2013.
But for the 12th century at least, which is the period of interest to me, the rules of both templars and hospitallers stated that a knight who taught leprosy must leave the Order and join the brethren of St Lazarus, who wore a black habit without insignia and it must have been the same for their sergeants.
In my opinion the knights and the sergeants of St Lazarus carried a simple surcoat (but rather sleeveless, not the "cappa clausa" of the Knights and sergeants Hospitallers…) like those of the Knights Templar, but black and without cross or badges of any kind.
And as everyone knows, sergeants are not as heavily equipped as knights, including in the military orders of the Knights of Christ.
To finish and to confirm what I think about this topic, I contacted the Chancellor of the Grand Priory of France, in the person of Chevalier Daniel Blanchet Magon de la Lande.
I hope he has the answer, or that he will put me in touch with an enthusiast or a specialist of his order for these kinds of questions.
While waiting for this miraculous answer, we should be interested in the number of combatants of this order, what battles with how many knights, sergeants and turcopoles?