"what are their strengths, tactics imployed, weapons and organizations? I want to know what type of troops the Chinese used. I know that the Macedonian army isn't solely based on phalanx, they also had light infantries such as the peltasts which guarded the flanks and rear. It was used very effectively by Philip in the Battle of Chaeronea in which the light infantry lured the Athenian Hoplites away from the Thebans and Alexander's heavy cavalry smashed the thebans. Alexander also had archers and javelin throwers in the front line and his most successful weapon is the companion cavalry. So one can't solely judge the result based on the fact that crossbow can shatter the phalanx because phalanx isn't the only thing that Alexander used. Alexander also had archers and javelin throwers in the front line and his most successful weapon is the companion cavalry."
Here is some good information by Yun from Sun Bing's manual.
The Wu - five-man squad in line astern.
The Dui - 10 Wu in line abreast (5 men deep and 10 across) 50 men
The Bo - Two Dui in line abreast (5 men deep and 20 across) or line astern (a square 10 men deep and 10 across) 100 men
The Qu - Two Bo in line abreast (5 men deep and 40 across) or line astern (20 men deep and 10 across) 200 men
The Square - made up of several rows of Qu, with the HQ in the middle of the rear row. Not necessarily a true square, can be rectangular. A favourite tactic was to place stronger Qu on the flanks, and then lure the enemy to attack the centre and be outflanked.
The Circle Բ - a Qu reformed into a ring, with the HQ protected within it. A highly defensive formation.
Dispersed Formation - increasing the distance between individual Qu in a square, so as to mislead the enemy or divide his forces.
Close Formation - decreasing the distance between individual Qu in a square, for strength in close-quarter fighting.
The Awl (zhui)֮ - A wedge (triangle with one point facing forward), a highly offensive formation. Also known in later history as the Male Formation (pin) (you'll see why later).
The Wild-Goose-Flight Formation (yan)֮ - A V-formation with two wings for enveloping the enemy and the HQ in the middle. Or an inverted-V for a defensive formation that can quickly be converted to offensive wedge. The V-formation can also be modified into a flattened U known as the Basket Formation (ji) or Female Formation ĵ(mu), for luring enemy wedges into the centre and then enveloping them.
The Hook Formation ֮ - A line abreast with the two ends sloping inwards to avoid being flanked. Probably most suitable for archers or crossbowmen.
There is never a standard organization in Chinese armies because like the later Byzantine, they do not want the enemy to know how much troops they actually have. These divison could be aranged differently, for example, the standard is a Qu, higher would be the Jun(army) which could range anywhere between 2000-6000).
The typical tactic of Chinese warfare is very different from that of west, with its more powerful missile, Chinese warfare depend far more on firepower than shock as the ancient classical west had. Most of the time except when one army has the higher ground, the two army would be a great deal distance away in looser formations sometimes digging trenches or hide at slopes until enemy fire lessens then they would charge with their speed infantry, thats how Qin won its battles. This is of course ignoring the other elements to a battle such as skirmish and surprise.
"Also, with the exception of missiles I would say that Alexander the Great's troops have superior infantry since they are probably heavier armed and has more shock power.
The Phalanx formations would just smash through the Chinese dagger-axe infantry lines in my opinion. Surperior stabbing distance and deeper ranks. Unless that is if they get surrounded and massacred."
Military battles are far more complex than just heavy armed trample through light ones, unless you're talking about a narrow hill in the case of Thermoplae.
Warring state armies especially that of Qin was not as heavily armed, Qin's armour unlike many other states was not very heavily armoured, their armoured troops did not have full protection and rarely carried shields. Qin sacrified protection for mobility, and from the examination of its armament, it would indicate Qin always took the offensive. From examination of the Qin formation, it has a vanguard force, which was a deadlier version of the Greek archer and peltasts of the front and rear. The vanguard is made up of three rows of crossbow and bowmen, using rotational fire, and could have a pavise for protection. The bolts of their weapon are unmatched in fire power by the Macedonian troops. And they could punch right threw a hoplite shield(The first emperor of China, Cotterell p.48) They are lightly armed for speed, so they could retreat with speed and fire from far away. Their agility and speed along with the light spearmen behind them and those guarding the flanks when utilized correctly would be impossible for an enemy to catch it off balance. They are similar to the role of the Peltasts, but more efficient, for their archer has far stronger fire power. Those behind the vanguard is the chariot and light infantry that accompany it, the chariot are light and used to breakthrough enemy formation with speed while the light infantry and the heavy ones behind it charge to exploit the opening, these troops ar eheavier armoured than the rest for they have to do hand to hand combat, but the strong part of Qin was its Halberdiers which inflict great damage on nemy. Behind are rear guards which guard Qin's rear.
Qin has a left Wing divison, which was designed to be far more mobile, they wore little armour and carried no shields, they have archers in the front, light chariots and cavalry along with light infantry behind. These are used to attack with great speed on the opponent flanks which is a common tactic.
This organization is as follows:
A vanguard of archers together with unarmoured infantrymen.
A cavalry unit occupying the left flank.
A chariot unit occupying the right flank.
A main unit of cavalry and chariots subdivided into 8 columns occupied the center in a rectangular formation.
A cavalry unit covered the rear.
In general, warring state army were not as strong in shock power, but are far more flexible and mobile, this formation was known in Chinese military lore as `Concentric Deployment', a tactic in which each unit could fight either independently or as part of the whole. In another word, each Wu, Dui, Bo Qu, Jun could fight by as separate units and move independently or together. Their different arms in proportion enable greater military movement and orderexecution while the difference enabled fighting as a whole like a phalanx or when the formation is broken fight as individual unit with halberds, Ji, spears and swords. Whereupon the typical phalanx could only move forward and backward, with support light infantry it could fare well, but was still outmaneuvred by the legions due to its rigidness, since the Roman was also flexible it could surround and outflank the Phalanx. This is of course only taking account of the infantry melee, not about the firepower and cavalry role. The conclusion is you can't blindly assume Qin's army would be outfaught by Macedonian infantry simply because it is not as armoured. Qin emphasized on speed and valour for armour which is one of the reason it was so successful, also Greek military seem to stick to the concept that heavy infantry is always superior to light, thus they never allow the light to engage the combat with the heavy, this is exactly different from China since Chinese manual emphasize the role of light infantry is to outflank the heavy infantry. without through knowledge of Chinese warfare, the Phalanx general could very well be surprised when a light infantry hit its flanks as it was against the general rule.
"I don't think crossbow alone would be enough to win, because Alexander's troops as already said, isn't entirely of phalanx, its his combined arms technique that made him successful. Also, with the exception of missiles I would say that Alexander the Great's troops have superior infantry since they are probably heavier armed and has more shock power. "
"How would Chinese crossbowmen slaughter the palaynx squares if they advance in tortoise formations?"
First of all testudo is a Roman formation not Greek, get that straight. Crossbow would take heavy tole on the Macedonian phalanx because of the poor defense equippment of the time. According to expert studying the crossbow from the terra cota pit, the bolt could rip straight throw the Greek or Macedonian shield with ease at 200 meters. Greek shields would have been easily shattered by Chinese cross-bows in the bookto "5000 years of Genius - Ancient Chinese Inventions", there explicitly mention that the shield wall would have been easily shattered when it approaches.
The only way that the Phalanx would be successful is if had the ground advantage. But considering they are invading the Qin has the mountainous terrains. Without letting the phalanx getting too close Alexander's tactic of using the Phalanx as a shield and attack with the cavalry would be very difficult to excersice. Manuevres he pulled on the Greek states such as luring the heavy infantry away frwith light ones would have little use since the warring astate military know very well of these tactics. His archers would be outfired, while if he attempt for a surprised campanion charge, it would have been repelled by the Qin vanguard and rear light infantry protection, these units are espcially there to guard against unexpectded attacks preventing the Qin army from ever getting caught off guard. There crossbow bolts would have been deadly against cavalry charges that are not fully armoured, as demonstrated against the Xiongnu cavalry, while those that manage to cross the barrage would have to face the light Qin halberdiers and Ji users especially designed to cut off cavalrymen. So most likely that an initial encouter would have completely caught alexander off guard since he never faced such weaponry and tactics unless he have a through understanding of the ways that Qin faught.