Why Turkish Medieval / Early Modern Era armies were so massive (compared to their enemies) according to sources from that time? Well, if you count camp followers you get enormous strength of armies. For example the Turkish army in the battle of Vienna in 1683 had 50,000 horse-drawn wagons with it (and we must count one coachman and a few camp followers for each horse wagon). So apart from 150,000 soldiers the Ottomans would have probably 150,000 - 200,000 camp followers (including coachmen) with them at Vienna - and 50,000 horse-drawn wagons (one wagon for each 3 soldiers). The same would apply to European armies of course. And it seems that Turks actually had a habit of counting also camp followers and even horses and camels as "army strength" in their official military documents. I guess it had some propaganda impact on their enemies. But they didn't count camp followers and horses when counting casualties, on the other hand. For example Polish 17th century soldier Jan Ostrorog commented the discrepancy in numbers given on Turkish forces in the battle of Chocim in 1621. Turkish own counts said that their army at Chocim in 1621 was 300,000 Turks and 100,000 Tatars - in total 400,000. While Polish envoy who was also acting as a spy during his mission to Turkish camp, wrote that there were not more than 150,000 Turks and not more than 60,000 Tatars. And in fact the first number most likely includes all men and horses and the second one probably includes all men (including camp followers). And here is how Jan Ostrorog explains these great differences in numbers: "(...) Sir Zelenski [that Polish envoy] counted their forces using Polish method, which is considerably different than Turkish method - in the Turkish army they count separately each living creature, for example if they have a mounted knight and this knight has another horse, or a mule, or a camel - then they count all of this separately, and that's why they get so huge numbers of their armies (...)" And Ostrorog concludes: "(...) That's why when there will be a 10,000 strong Polish force, there will still be more actual soldiers among these 10,000, than in a Turkish force which is said to be 20,000 strong, or maybe even in a Turkish force which is said to be 30,000 strong (...)". Another Polish envoy - Krzysztof Zbaraski - who visited Turkey few years later, wrote: "Forces of the Turkish tyrant are bigger on paper than in actual armies, because when they count strength of their forces, they count both men and horses"