[quote=Dinh AaronMk]
Well as the overall rule I take to consideration is that a medieval lord can raise an army of 10% of their population (~10% of which would be devoted to offensive operations). Ten percent of 350,000 would be 35,000. So they're not at that limit before they experience long-term economic deficits.And if they're a sort of holy order with land, then many of those recruits could also be foreign proselytes who came to them for whatever reason: adhering to their faith, needing to start again, whichever. So they could not actually be "natives". Most of these could also pull double-duty, being an island have a trade fleet would be vital to their economy, so some soldiers could pull double-duty as an armed merchant marine: active in the order's mission but keeping the cogs of economy moving and pushing out their exports.
[/quote]

General rule of thumb in a pre-industrial age is 0.5% of the general population, 10% is impressive even in a modern society. There are many, many different estimates about the sizes of the army and the population in the Roman Empire; one of the most commonly quoted interpretations place them at 350,000 combatants among a population of 50 million by the end of Augustus's reign, or in other words the fighting components of the army made up about 0.7% of the population at a time when the core of the Roman empire was at peace while the frontiers (particularly Germany, Syria, Mesopotamia, and Numidia) were in a state of near-constant warfare. 

That's just a basic estimate from a highly militant and organized state.

In any case I don't really care too much this being a fantasy setting and all, but that number did make me do a double take. (and I got the estimates closer to 6% rather then 10)