The mongol ability to take was impressive their ability to conquer is actually less so. Conquering entails holding what you take and the mongol empire didn't last a generation before reverting basically all of Temuchen Khans' holdings to conquered.
I agree, they certainly did not consolidate power in a lasting system as neatly, and compared to their prodigious ability to seize territory it falls short. However, while the united Mongol Empire lasted a generation or maybe slightly more (Genghis was fairly long lived), I think judging the empire by this alone is unfair, particularly since the Mongols and other peoples on the Eurasian steppes tended to partition their empire among different children rather than going for a united inheritance. This is pretty much what happened when Genghis died and you had the Yuan, Blue/White Hordes, Ilkhanate, and the like. And I think it is worth noting that most of these states tended to remain successful and stable for at least a generation further, and in several cases well beyond that. What else can we make of something like the Golden Horde or the Central Asian Genghisid successors, who lasted well into the modern era?
So on this front I think it is worth noting that their ability to conquer is still more impressive than that description indicates, given the relative success of the heir states. Though it still fell woefully short of what was necessary in the long run.
It had a far reaching influence, but mongols probably would have never made it into Europe proper where their hit and run tactics would be hampered by the varied and less-than steppe-like terrain.
I think part of the issues with this are twofold, though this raises several good points.
A: How do we define "Europe proper" in this sense? Since the Mongols did invade well into Hungary, Poland (which reached much further West in the medieval era), the Order State, and in one memorable case chased King Bela of Hungary all the way to the Adriatic. Certainly they had a much harder time of this than many think (the Battle of Mohi in particular was much more costly than is usually portrayed and nearly ended in defeat), but they showed a decent ability to do it.
B: I agree the hit and run tactics would be hampered by the terrain and the insane degree of fortification that was present, but if the Mongols had been totally incapable of coping with these challenges they never would have subjugated the Southern Sung. Who after all were a highly organized rump state with a formidable navy, natural defenses from the river lines, and fortresses. The Mongols showed an admirable ability to assimilate technical expertise, including siege work, and the danger of horse nomads bearing siege engines in Central Europe had been shown by the Maygar threat a couple centuries earlier.
I don't mean to pooh pooh European defenses or military abilities or engage in Mongol wank, but I do think that even outside of their natural environment the Ordas were still one of the most adaptive and formidable military forces on the planet at the time, as well as probably the best informed in terms of politics and strategy. I do not think this would be an easy fight. I do think the Mongols would have been unable to sustain the conflict so far from home in the end, but they could certainly cause in ungodly amount of damage (as they did in Poland and Hungary).
As for crossbows in warfare. I think what you would see is actually inversely what you'd see with gunpowder weapons. Crossbows became bigger and badder requiring braided wire and cranks to pull back making the cross bow as a handheld weapon woefully outclassed by armor. So the crossbows would become like two-man bazooka teams instead of guys holding rifles.
A very good point, and you are certainly correct that as the demands of warfare shifted people got a bit desperate about how to store more and more force in a crossbow before a shot. And one of the ways they did it was desperately trying to find a way to make it bigger. The issue I have with this interpretation is twofold: one being that in some ways they already had gone to the extreme of making it bigger (as we see with Ballistas, and I remember this one drawing of Leonardo da Vinci's where he proposed an even larger one), and we see a step back from that. Though partially because of the introduction of gunpowder.
And secondly- and likely more importantly- the reaction many people seem to have had to this was not making "Crossbow Teams" but trying to find ways to help make it easier for a single soldier to do it. One of these ways was the many intricate mechanical ways they used to create tension, but another was providing protection for the crossbowmen as they reloaded individually; this is where the idea behind the Pavise. This is not a perfect solution, obviously these wound run into issues if you tried to use them in the equivalent of an 18th century musket formation or against horse archers like the Mongols, but those could be compensated to some degree (such as experimenting with mixed formations like what Pike and Shot ultimately led to, or positioning them in cover).
Though on that note, since larger pavises tended to feature two people- a Crossbowman and this "squire"/groom to lug the shield- that might lead to what you describe.
The crossbow wouldn't become viable as a one man weapon until modern metallurgy and carbon fiber most likely.
I disagree, especially given how there isn't really a better option on the table for portable anti-armor firepower (however imperfect it is). And the performance of groups like the Genoese and the Hussites show that it could certainly be effective against well equipped Renaissance men at arms. It is certainly less powerful and thus less safe than a whole lot of muskets, but if you have to make do it isn't that too bad.
This video does a decent-ish job of it (though the way it is just propped up isn't great).
A few things are worth noting: One being the overall durability and protection of this thing, which is formidable indeed. But secondly the damage it Does take.
Now imagine you have this skirmish line or so with maybe half a dozen or so people firing at it and you can imagine the kind of damage this *could* do. Again, not something that could never be overcome (as the Imperials showed several times, ditto English cavalry), but it is enough to make me think this is a valid weapon even before the development of modern tools.
As for horses. I'd still think they'd go out. This scenario doesn't necessarily preclude the invention of the internal combustion engine. Motorcycles don't need to be fed or walked and can carry a lot more armor without complaint.
Hm, a good point. Though they also tend to have poorer balance as they're made today, especially if we decided to tilt with a lance in full plate. So I would imagine the bikes of the future would probably be heavier in military use. Which also means they might be able to be outmaneuvered (if not necessarily defeated) by scouts or skirmish troops on ponies or the like.
Still, I do imagine that this would be welllllll into the future, well after what we saw IOTL because of the close relations gunpowder and gunpowder weapons had to the technologies that historically kindled the industrial revolution and the ICE.
This leads to an issue because no man-portable crossbow could really reliably hope to stop an armored car packed with knights.
Agreed. In which case your best bet would probably just to throw up your hands, say "Screw This", and try riding back to your castle/walled commune and hope just staying clear would be ok.
Or maybe try and smash it under a big rock like what you'd get from a catapult or its' cousins. But in any event, not the best countermeasure.
Though this might be counterbalanced by your side having armored cars as well. And it does make me wonder about some kind of crude attempts to use ICEs or similar devices as substitute projectiles (like trying to rev up an ICE and fling it at a castle wall in the hopes of damaging it?).
but there would be a greater disparity assuming that no gun powder means no dynamite, which would mean less focus in the world of explosives in general.
Agreed, no contest.
In fact chemical and biological warfare might reach horrendous used in this world as it's hard to make battle armor that can last against it until some kind of modern bio-hazard gear is invented.
Agreed. This was something I considered raising in my first post; that biological warfare becomes that much more common and deadly. We know crude attempts at it were used throughout history, what with the poisoning of wells and water bodies and firing diseased bodies into besieged targets. It seems like the Mongols did this particularly at Caffa. And in the lack of some kind of cannons, I can imagine it being looked at more and more intensely as human understanding of disease goes on simply because there are so few great options to knock through competently built fortifications in this setting.
So gunpowder is out, plague is in?