@Grob0s0VBRa So... basically, it's like tanks in 1930s, engines the size of a house with main gun the size of a broom? That said, although early-war Churchills are house-sized pillboxes the late-war variants are both sturdy and powerful in their own right. Perhaps there could be some sort of upgrade kits to their weapons as later variants, like with more coaxial guns and rocket launchers and such?
.
.
Granted, the issue about non-chemical weapons is that the energy (and thus damage) output available is directly tied to the reactors - without a powerful enough reactor, you can't power the guns. With a chemical platform (including chemical guns and rockets/missiles), as long as you can support the weight (and recoil) you can use it.

@ThomasRoderick
Spaced armor goes brrrrrt - this is exactly about the Mantis, plus it's power core is not so compact ( for example latest variant has its core in the rear,partially exposed because of ammo storage that is right beneath the turret)
Nation goes big sometimes, the reason might be speed,overall durability, ability to carry specific equipment and weaponry. And yes, re-use of civ-tech exist for them.
Walkers and mechs usually bigger than tracked, wheeled and hover vehicles.
Tech level connected with unit size, yet there is nothing of T2 to compare with (greater tech level = greater bookshelf; that how it sounds in my head )

@Grob0s0VBRa So... if it's a T1, why the size? IIRC the NATION is not known for making mobile walls (British infantry tanks * cough * * cough *) so "the size is for armor and shield generators" wouldn't stand, and as far as practical units go unless the size is due to they're made with civilian parts and thus don't have enough power/volume ratio to power the weapons with a smaller chassis...

@ThomasRoderick Production restrictions a.k.a. Tech tier.
All the machines used in armed confrontations are 3D-printed on field factory assemblies/conveyors using converted/reused materia that environment may offer. - The Art Of War, post-Empire time
(Simple things built using simple instruments, because of cost and time, so it is not THAT underarmed for T1. Predator has a support weapon system (those missiles), and Mantis (all of them) is more durable (kinda MBT), plus both chassises are actually outdated (and retired from official use) pieces of military genius.)

Hm, should i mention spoiler alert?

Ah and actually i want to practice with T1 kind of builds for a bit longer, cuz nid to git gud, again (just compare my draken and all further uploads...) and develop factions styles further, more distinctive they be must.
Anyways, all i may need is... time? There is much to be done, heh, too much planned
oof

@Grob0s0VBRa
STILL NOT 'NUFF DAKKA YER GIT! ...LOIST YER SWOICHED DA BIG SHOOTA FER DA SOOPA-SHOOTA... STOILL, TA MOIKE DIS STOMPA PROPA' ORKY, BOLT TWO UVVA' BIG SHOOTAZ TA DA SOIDEZ, DA ROKKIT LAUNCHA TA DA TOP, AN' ANUVVA' BIG SHOOTA TA DA GOB IZ A GUD START...
.
I wouldn't say it got nearly enough dakka (no coaxial MGs and/or remote weapon stations), but at least what it does have is more powerful... Hell, combine the weapons on the two models and put a coaxial HMG on both sides of the main hull and I'd call it a good start.
.
.
"Just in time"
Yup, a day before I start to ramble about this not having enough guns... The NATION doesn't seem to carry that many guns on its platforms, given the last NATION walker is also underarmed for its size.

@ThomasRoderick
Moar Dakka?