A 100 ton mech is probably one of the most heavily armed mechs on the battlefield and its role is to inflict serious damage to the enemy.
On the other hand, 100 ton mechs are big, generally very slow, and often the first priority target.
This makes balancing their offensive vs defensive characteristics a very important matter.
Durability
Durability of a big assault mech has direct relation with how well it can roll damage based on its geometry and torso twisting agility, as well as how much exposure the mech needs to bring all its weapons to bear on the enemy.
- Generally, humanoid torsos are easier to shield due to having a narrow side view which is often protected by the arm geometry.
- The faster a mech can present its shield side to the enemy, the better it can avoid taking damage to the more important components; given the the mech has a good geometry for the shielding technique.
- Exposure when firing is another aspect that can define survivability of a mech. Generally a mech with higher hardpoints has better chance of avoiding incoming fire since it can hide most of the mechs geometry behind terrain. This is very important in case of slow 100 ton mechs, since they can not go back and forth into cover effectively.
- Range of engagement is also important when analyzing a mechs durability. Short range assault mechs receive more punishment than long range snipers and rquire more agile movements when they are shielding their components.
In my opinion, armor quirks are a must if a mech requires exposing its entire torso to fire due to low hardpoints.
Since torso agility heavily impacts how well a mech can protect itself when there is no cover around, it becomes an important durability factor in close range engagements and full exposure.
Important note: armor quirks vs structure quirks
In some chassis armor and structure quirks are used as something to differenciate between variants. On a first look, it appears that they both count towards the total hitpoints of a component in the same way, while in reality structure quirks are largely inderior to armor quirks due to the existence of critical hits which will often cause loss of weapons, and recieving more internal damage.
A mech variant with structure quirks is instantly worse than a variant with armor quirks in terms of durability.
Torso pitch
One of the key aspects in how effective a mech can utilize its weapons is the torso pitch value. Sadly this important number is often overlooked by players and sometimes the devs.
This becomes increasingly crucial if a mech has the majority of its weapons in the torso.
Unlike torso yaw, torso pitch limit can not be compensated by leg direction which often leaves the mech completely out of the fight and unable to shoot (e.g. UAVs, while being under constant indirect fire).
In my opinion mechs with majority of their weapons in the torso should benefit more from torso pitch, depending on the hardpoint type, availability of arm weapon options and hardpoint locations
current state of 100 mechs
The current state of 100 ton mechs in terms of the above mentioned aspects are summarized in the following graph:

The following observations can be made in the above graph:
King crab: The main guns on a king crab are generally in the arms with no lower actuators and are mounted low and wide. Threrfore, high torso agility and armor quirks suits this chassis well. However, having the highest torso pitch value (while being good) is not really a big factor.
Kodiak-SB: With majority of the weapons in a humanoid torso, and large number of missile hardpoints, the Spirit Bear is well suited for close range combat, specially when its complimented by a large MASC. Those two aspects shoueld grant this mech reasonable torso pitch limit and fast torso twist respectively. Something that is missing in the current state of the game.
Lack of armor quirks can be justified due to cockpit level weapons, lighter clan-tech weapons, and very big engine.
Kodiak(except 3 and SB): Currently the kodiaks other than 3 and SB are reasonably balanced with regards to the above mentioned characteristics. Though slightly higher torso agility can help bring them more in line with their more powerful variants.
Kodiak-3: No other mech in the game could or will ever be able to affect balance to the extent KDK-3 did. This mech may seem to be in a reasonable place at the moment with high mounted and often long range clan heavy ballistic weapons, combined with a good torso geometry. However, considering multiple nerfs to the weapon systems this mech used in the the past and other assault chassis like the MCII-B, the KDK-3 is being outclassed at a role it once excelled at. Slightly more torso pitch and moderate torso agility buffs may bring this chassis back into top of the line assaults.
Annihilator: As the slowest 100 ton mech, the annihilator has low mounted hardpoints distributed between arms and torsos. This justifies the armor quirks that this mech is benefitting from. Also, due to the overwhelming amount of firepower this mech can bring, the torso twist agility seems to be in a good place at the moment. However, this chassis can still benefit from slightly more torso pitch limit since the majority of its back-up weapons are in the torsos and the painfully slow mech can hardly relocate.
Direwolf: The worst torso geometry possible for survivability, locked slow engine, and low mounted main guns in the arms should grant this mech the benefit of having armor quirks. I think this is a fair assessment since individual components on this mech can be shot from anywhere and any angle. I'd argue that slightly faster torso twisting would also be good, keeping in mind that this chassis is the most heavily armed mech in the entire game, capable of one-shotting targets over long ranges. Other then that, due to heavy emphasis on arm mounted weapons, this mech has enough torso pitch limit.
Atlas: Nearly EVERYTHING is wrong with the current state of this mech. All of the weapon hardpoints are low mounted which should grant this mech armor quirks (armor quirks for all variants). Except the hero variant, This mech is crit-slot starved with the highest concentration of hardpoints in the torsos and little hardpoints in arms. this is enough of a reason to justify giving it the highest torso pitch limit which is in complete contrast to its current state. the torso geometry and high emphasis on missile weapons means that this mech is well suited for close range combat; therefore by taking all other limitations into account, this mech should get the fastest torso twist speed among 100 tonners as well, which again is in contrast to its current state.
Overall, I've summarized my suggestion in the following graph:

On a final note I wanted to say that because the skill tree nodes for torso pitch limit are percentage based, the mechs that need it the most (100 ton mechs) get less benefit from it, while lighter mechs with enough torso pitch limit get even more out of this skill node
Please feel free to discuss.
Edited by Navid A1, 27 December 2017 - 07:00 PM.