We don't have precise figures for the membership of the military orders or for the non-combatants that resided in their strongholds, but what evidence we do have suggests that the number of professed brethren, i.e., full members of the order, were never particularly great in number and would not have made up the majority of any garrison. Instead, secular, often mercenary, troops would have made up the majority of any military order army or garrison. The Templars had fifty knight-brothers, thirty brother-sergeants, fifty turcopoles (native light cavalry) and three hundred archers at their castle of Safed shortly before it was lost to the Saracens in 1266. These numbers show that less than twenty per cent of the fighters were actual members of the Order. That figure would drop even further if we knew how many non-combatants were also at Safed. With most military order garrisons, the numbers of professed brethren were probably in double-figures, not triple. In 1268, the master of the Hospitallers claimed to have only three hundred brethren in the whole of Syria. At the fall of Acre in 1291, the Templars and Hospitallers were estimated to have fielded about thirty knights each and the Lazarites twenty-five.

The case appears to have been in the Baltic. At Ragnit in 1289, there were forty-one professed brethren, but these were supported by a hundred secular squires (we don't know how many archers or secular non-combatants there were). The Livonian Rhymed Chronicle claims that there were only fifteen brethren in the Teutonic Order's garrison at Terweten in 1279. In Iberia, when the Templars were arrested in Aragon in 1308, the largest garrison of brethren numbered just fifteen, at Cantavieja, and not all of these would have been combatants.

We have some precise figures for the number of brethren and secular employees in the military order estates in the West, which can give us a little insight into how many non-combatants may have been in a stronghold in the East. A report survives from 1338 listing the staff, property, and finances of every Hospitaller estate in England, Wales, and Scotland. Most houses had only two or three actual brethren and a few secular staff. Ansty Preceptory in Wiltshire, for example, was home to John Dingland, the preceptor and a brother-sergeant, John of Winchester, a brother-knight, and William West, a corrodian (someone living off a Hospitaller pension, often a former secular servant or important donor). Secular staff employed at the preceptory included a chaplain, three clerks to collect the confraternity (an associate membership of the Order that the laity could join), the preceptor's squire, two stableboys, a cook, a baker (who also did the brewing), a boy to assist him, and a porter. Of these fourteen people, only John Dingland and John of Winchester were actually Hospitallers. A similar ratio of brethren to secular staff probably existed in the Order's strongholds in the Levant as well.

Sources:

Alan Forey, The Military Orders from the Twelfth to the Early Fourteenth Centuries (Basingstoke, 1992)

Lambert B. Larking and John M. Kemble (eds), The Knights Hospitallers in England: Being the Report of Prior Philip de Thame to the Grand Master Elyan de Villanova for A.D. 1338 (London, 1857)

David Marcombe, Leper Knights: the Order of St Lazarus of Jerusalem in England, c.1150-1544 (Woodbridge, 2003).