The following was my post 1 year ago on the similar topic Alexander VS Qin, starting by analysing the Qin's terracotta army:
1. stone armor: they wouldn't produce a brand new design just for the tomb, would they? Those stone armor however were based on the real armor, isn't a simple logic ? Futher, the emphasis here are
-A. the flexible design that fits right into modern human body studies, akin to modern age armory design.
-B. the sheer amount of time consumed to make such armors today : 344-444 days per armor. And those holes (square and round shaped) of 800 pieces were connected together by hair-thin metal strings!! Whatever Qin was doing, its military mass production facility must be humongous to produce just that 8,000 stone armors for the already-discovered part of the tomb alone (surely there could be more, or much more such armors in the undisvoered parts of the tomb, and those were not the only armors that Qin produced at a time which included the real armors for the entire army, logically were only a tiny fraction of them). They should be identical to the real metal armor, because like everything else Qin emperor wanted a REAL DEAL for everything in his tomb to protect him in afterlife, not some fancy models. So, imagine the true size and high tech - streamlined process of the production, quality control and size of the real military complex and underlying skills and economy size they reflect - that's the point.
2. On those >90cm bronde swords: the keys are
-A. chromium plated high tech deployed was 2,000 friggin years ahead of anything Alexander could come up with. That was only the known part of Qin's technologies. Are you certain that was the only part? It was so advanced of its time that makes you wonder what's more in the undiscovered tomb that we don't know yet.
-B. Alexander used bronze weaponaries? short bronze swords <60cm. Which side do you think would be slaughtered if an equal number of infantries from Qin and Alexander confronting each other, one using 90cm swords while the other 60cm?
3. those 2 life-size bronze chariots unearthed: assembled together by 8,000 standard pieces! including the tiny bronze metal strings placed under horses' mouthes - as thin as human hair. What kind of friggin technologies to produce those 2,200 years ago? Go to a 21th century mass production weapon factory, say, a M-16 rifle factory, do they have 8,000 pieces for one M-16? 800? or 80 pieces? What do 8,000 standard sub-pieces mean to you? Go to a Leopard MBT facotry in Germany today, do they have 8,000 standard sub-pieces for 1 tank? Or go to a Toyota factory and ask them the same question. Again, just pause a moment here to imagine the sheer sophitication in industrial design, production processing ( including Just-In-Time style stock delivery known from Toyota in modern time), degrees of modernity implied in these factories just for production and assembling of these 8, 000 standard pieces, and the sheer standard of quality control... underlined by those 2 "simple" bronze chariots. Yes, they were just command&control chariots, not combat ones, but technologies they represent would make the combat ones worse, the same or even better? Did Alexander have anything remotely similar?
4. on the 40,000 (from only already discovered part of the tomb )parabolic arrow heads that were indeed modern bullet-alike, imagine the sheer accuracy of these suckers! the sheer deadly piecing strengh after combining them with crossbows (almost a semi-automatic machine gun), multiply that with Qin's huge @rse numbers. How could it be possible for Alexander to deal with Qin's quality and quantity? Furthermore, what most impressed me is the margin of error of mass production of these arrow heads' parablic shapes, which is said to be measured in terms of about 1 mm - almost equivalent of making them again using modern high precision German machinaries. In other words: 40,000 friggin "IDENTICAL bullets"! Picture that.
Above are only a small part of known FACTS (proven by the ongoing new discoveries of relics of the tomb), not hearsays, of Qin's awesome high tech of designs, numerous advanced industrial knowhow centries ahead of its time, and nevertheless Qin's HUGE arse military complex production facilities a bit akin to today's USA+China putting together in relative terms. What Alexander had at a time to match these in any shape and colour?
it's a bit like Somalia Vs USA? an overstatment? perhaps not.
The similar could be said on Roman VS Han. The Romans were much weaker on virtually anything you care to measure vís-a-vís the Han. The Romans were lucky that they didn't border on Han Empire really.