I notice many games and movies often portray when heavy infantry armed to the teeth with-every body part covered in metal and using heavy weapons such as pikes- battle lighter infantry such as say macemen wearing just leather as armour or militia armed with just thick clothing and a sword, its always portrayed as a steamroll in which the heavy infantry squashes the lighter armed enemies like a tank. Literally its portrayed that the heavy infantry square in walking over the lighter infantry and squashing over them like an unstoppable bulldozer going over a neighborhood block of houses.
This is especially true if the heavy infantry is armed with pikes and forms a column wall of spears or is armed with long sword and shield and forms a phalanx style formation. Even if the lighter infantry is well-disciplined and organized, the heavy infantry in rigid spear columns or sword and shield phalanx blocks will slaughter the lighter infantry and push through rather easily.
Even in cases where medium weight infantry that is still somewhat lighter is using the same type of weapon and formations (pole arms in a spear wall) and is quite well-armored (chainmail), just the fact the heavy infantry is equipped in metallic armour such as plate armour or Hoplite bronze uniform is enough to leave it as a slaughter as heavy infantry rolles over the lighter infantry like a tank over trenches. Despite the lighter infantry still being well-equipped and using the exact same formation and weapon.
Is the gap that great? Is simply equipping one unit entirely of heavier armour and weapon automatically mean victory? Or even just a armour one class heavier and better (plate mail vs chainmail) even if the enemy infantry is well equipped and slightly lighter in class (medium infantry vs heavy infantry)?
I ask this question because despite the stereotype as often seen in movies like LOTR, I was playing Shogun: Total War and an interesting thing is that I was able to win several battles against the heavier Yari Samurai and NoDachi Samurai by sending Samurai Archers to attack in melee in a situation perfect for heavy infantry (bridge battles or battles in a flat plain). Although the Samurai Archers ultimately lost most of the time, the NoDachi or Yari Samurais took too damn long killing the archers that I was able to prepare a trap and send my cavalry to out flank them. Even in cases where I could not maneuver my troops for flanking, apparently my light Samurai archers were able to hold of the elite NoDachi or Yari Samurai in battle to not only exhaust them but inflict signficant casualties. So when I finally sent my real infantry as my Samurai archers were fleeing from collapsing morale, my own Ninganata Samurai were able to defeat the now-exhausted NoDachi or Yari quite easily.
So I'm wondering based on the Shogun:Total War battle how accurate the Hollywood stereotype of Heavy infantry steamrolling lighter ones is? I mean other games such as Age of Empires and most movies such as Troy shows even well-armoured troops using heavy weapons getting slaughtered quickly when fighting heavy troops (especially if the heavy troops are in a rigid shield wall formation or spear wall formation as seen in Troy). Even if the lighter troops try to form their own wall formation and are only slightly less armed (they're wearing chainmail with parts of plate as opposed to the fully plated heavy infantry and both are using long pikes).
Is real life more accurate to what I seen in Shogun:Total War?
I'm sure you won't be too surprised to learn that this is not how pitched battle actually works. The relative "weight" or "class" of armour is something that modern game designers are far more interested in than actual historical people; it is a way for developers to quantify and implement a system of incremental improvements that allows the player to get an edge over their opponent. Similarly, the notion of tiers of infantry weight is created purely to satisfy the needs of game design. The Total War franchise in particular is built around a rock-paper-scissors concept of close combat, in which particular units are specifically constructed to outperform others in certain situations, forcing the player to vary their playstyle based on the challenge they're facing. Given the setting in which all factions field broadly the same units, Shogun 2 makes this artificial concept more obvious than the other games in the franchise. Yari Samurai have high defence and weak attack, Katana Samurai have high attack and weak defence, Naginata Samurai have heavy armour but are not as powerful as the others in their respective specialist roles. If you're wondering how your engagements can have particular outcomes, the answer is simply in these unit statistics. None of this has anything to do with historical reality, in which the roles of infantry are much more broadly sketched, strengths and weaknesses are much less precisely weighed, and contingent factors are much more decisive.
Warriors of the past were not so concerned with the marginal superiority of particular types of weapons or armour. Their choice of equipment was determined to a far greater extent by cultural and economic factors, and, generally speaking, real-life battles were not decided by what type of cuirass the men in the main line were wearing. While more comprehensive armour might affect survivability in individual combat, it won't affect the weight of a charge (a fairly nebulous concept to begin with) or the cohesion of a formation. Far more important to the warrior was the support of his comrades and the trust in the commander; far more important for the commander, aside from critical factors like numbers, terrain, weather, and supplies, was the troops' ability and willingness to play their part in his plans.
A few examples illustrate the point. According to Herodotos, the Greeks had the edge in close combat against the Persians in the decisive battle at Plataia in 479 BC because they wore heavier armour, so that the Persians fought "like naked men against hoplites". We're not sure how true this claim was, given that both sides would have worn metal armour but neither side will have been uniformly armoured, but we can leave this aside for now and take Herodotos at face value. What he does not describe as a consequence of superior Greek armour is a Spartan formation advancing like a "steamroller" or a "bulldozer". Instead, he sketches a protracted, bitter engagement, in which the Persian Immortals performed desperate feats of strength and valour to break the Spartan spears and tear holes into their line. Uphill fighting on broken ground and mounting casualties could not deter them. It wasn't until their commander Mardonios was killed by a Spartan with a rock that the Persian morale collapsed and their battle line finally crumbled.
In battles of Greek against Greek, there is not a single case in which the relative amount of armour worn by either side is even mentioned as a factor in the outcome. Greek tactical descriptions assume only two basic levels of infantry "weight" - hoplites and missile-armed skirmishers - and take the broad similarity of the equipment of these groups for granted.
Meanwhile, in Tacitus' account of the rebellion of the Aedui, he notes how the rebels fielded a front line of men armoured head to toe in plate mail, intended to present an immovable obstacle to the Roman legions. In battle, however, their heavy armour prevented these men from using any weapon effectively, and the legionaries soon discovered that while they were impervious to attack with swords, they could easily be brought down with axes, picks and spades, and once they fell, they could not get up again. Their super heavy armour proved little more than an encumbrance and did nothing to affect the outcome of battle.