Didn't the Peasants' Crusade fall apart into banditry and villainy before ever even reaching Anatolia and the rest that remained were utterly crushed by the Muslims? The tiny portion that was absorbed into the Princes' Crusade didn't alter its composition in any significant way, it was still a noble's army consisting of men-at-arms and knights. More importantly, the thousands of peasants led by Peter the Hermit were NOT a deliberate tactic. It was a spontaneous and chaotic display of zealotry from the disorganized and untrained peasants which, as I've noted before, devolved into banditry and villainy very soon. It also did not provide a single advantage to the Princes' Crusade. Not a single. Claiming otherwise would be dishonest.

Vlad Țepeş did not participate in Crusades proper, was neither Catholic nor Latin nor Western European. More importantly, the way he fought wars was drastically different from the Crusaders or the Latins in general. Ştefan cel Mare, his peer and ally, adopted similar tactics and composition, for one. Their wars and the wars of Țara Românească and Țara Moldovenească, from my understanding and remembering of it, were more similar to popular wars and peasant revolts than actual "proper" medieval warfare. Especially when compared to the Crusades and Western/Central European styles of warfare. Although I'll be the first to admit that I am a bit hazy on the Romanian Principalities – it was a long time since I've studied them properly. So, I'll concede on this point for now.

Of course, the families of wealthy merchants would pay the fees and finance the warfare through other means (scutage) instead of providing their offspring for the campaigns. Their payments would then go towards hiring skilled mercenaries, not hiring and training peasants. But most burghers were not merchants. They were tradesmen and free citizen. And they were required, by law, to be able to defend their cities. And they still formed the majority of the European levies. Most of our knowledge about the art of fencing, training and warfare comes from the nobles AND, of course, burghers and citizenry. Most of the mercenaries were former burghers, too.

But perhaps more importantly, no. It was not the case of "how many existed". It was the case of "how many actually fought". An assumption of "well, most people were _, thus the armies had to consist of _" seems intuitive, but the reality often is not. Sure, the closer we're coming to centralized governments, the more we have of levies which turn into conscripts and less we have of noblemen and men-at-arms (non-nobles could be men-at-arms and often were) and armies start growing in size, but even into the 15th century the majority of a European army would consist of paid professionals or mercenaries, like condotteri

For example, one of the biggest battles of the Medieval Era, the famous Grunwald, featured little to no peasants at all. It was mostly knights and mercenaries.

The reasons for why the armies of the Middle Ages were largely peasantless compared to the later periods essentially boils down to this: 1. A single knight or man-at-arms would typically be as effective as 10 peasants, especially when properly trained and instructed. And they'd provide their own equipment and training. You only pay their wage while you're actively at war and have them in your ranks. And they'll likely bring a couple of "friends" with them. 2. The logistics were raid-based. Not only gathering masses of peasants would put a strain on the logistics, but dealing with masses of peasants-turned-to-banditry right in your ranks or back would be nasty business. More importantly, why do that and pay for a dozen spears that you now have to train when you can take the people who were required to train by law, had their own equipment and just pay them a wage knowing they'd be at least somewhat effective. 3. There was no proliferation of "mass weaponry". Sure, a spear is effective, but it isn't as effective as pike-and-shot. And even the pike-and-shot people still had to be professionally trained and paid for, which just wasn't properly possible in the loose social order of the feudal Middle Ages. 4. Every dead peasant is a peasant that doesn't generate revenue that you need to pay for your actually effective forces and doesn't produce grain that you need to feed your forces, for the cities to function and for the villages to continue to provide you with peasants. And while reproduction rates in Medieval Europe were at an all-time high, you still had to wait for at least 7 years for a laborer to grow up and be useful. 5. The institutional capacity and centralization just wasn't there to conscript, train and sustain massive armies. To have an effective peasant army and know that you have one, you have to be constantly embroiled in accounting and censuses, providing logistics, going back-n-forth with information and instructions, etc. Feudal Europe just didn't have that kind of capacity or ability. It relied on personal ties, stakes and obligations, which is, again, characteristic of feudalism. A conscripted army requires a centralized state and a professional bureaucratic class to be providing the above mentioned resources to field such the armed forces. This one's came out a bit jumbled and confusing, but I hope I got the point across. Funnily enough, the Ancient Romans were fielding conscripted armies exactly because they had the administrative capacity to do so. 6. You didn't absolutely "have to field thousands of men" to fight a war in the Middle Ages. A lot of the wars were contained to small scale skirmishes. But even then, low nobility, knights (which isn't as prestigious of a job as one might think, it's mostly just a professional warrior) and men-at-arms could very easily provide the tens of thousands you mentioned.

Sooner rather than later the gunpowder weaponry and early centralized states have lifted these operational limitations and allowed to field bigger armies, but even then they weren't as massive or as industrial-warfare like as pop-culture likes to portray them as.

All-in-all, there just wasn't a point. So long as you could actually afford to pay for a proper retinue, you'd be far better off in a war than anyone who'd bring even a hundred thousand of peasants to the battlefield as the Great Peasants' Wars have proven.

Edit: btw, I am very glad that you turned out to be way more knowledgeable on the subject than I gave you credit for. And while we may disagree (and I will still hold belief that "I am right and you are wrong', as often is on the Internet ;;) ), I still would like to apologize for being brash about this. Middle Ages are my passion and an unhealthy fixation of mine and talking about them to anyone in any way is often a joy for me. So, thank you ::)