Sorry if I'm being arrogant, but after almost completing XCOM2 I've decided to put up some ideas for public discourse, and to go straight to where these ideas may be implemented. Caveat: I haven't played the original Long War because XBox.

To begin, I'd like to point out that a resistance movement developing two wholly new tiers of weapons is exceedingly unlikely, so stretching three weapon tiers into five like the original mod is a bit unfitting, it is, however, possible to add a research-based boost to coilguns (perhaps based on Sectopod tech?), and the jump from cobbled-together Gauss guns to plasma weapons indistinguishable from alien kit (despite the alien kit presumably still being equipped with self-destruct systems) is similarly unnatural. Where are the roughly-made experimental "Pulse" weapons, consisting mostly of ADVENT tech and firing blobs similar to alien plasmas in EU/EW? I'm also suggesting that these transitional weapons should have degraded accuracy and only be available in rifle and cannon sizes because Shen can't immediately nail down the delicate balance between firepower and self-destruction described in research project flavour texts, and bluntly overengineers her designs.

So, that leaves us with 3 2/3 of weapon tiers. I'll explain where the other third comes from after I rant about new weapon branches. Divided by class:

Grenadier: needs a lighter alternative for the Cannon. The return of the LMG has been much craved by the community; it should have enhanced accuracy, but lower damage, and lower ammo capacity (2, thus prohibiting its use with some abilities); the Cannon should have a nerf accounting for its bulk, probably just -1 movement. Also, a Bipod attachment for all classes would be welcome, with similar effects to (or enhancing) Steady Aim.

Sharpshooter: the return of the DMR (to which assault rifle upgrades would apply), most definitely, but also a range of sidearms:

• Light Pistol: our old derpy friend from EU/EW, still causing laughable amounts of damage despite firing several shots. However, because it's a compact, handy gun, it confers the Return Fire ability by default.
  
• Revolver: XCOM2's default pistol, loaded for bear (rifle rounds, maybe?), has the same accuracy as its derpy predecessor, but a broader damage range.
  
• Machine Pistol: a derivative of the Light Pistol, but delivering a whole lot of derp at once. Nice damage, but severe range falloff; however, because of the volume of inaccurate fire, it has the Stock effect of always causing 1 Damage.

All Non-Rangers: weak melee attack, Bayonet attachment (yes, even to sniper rifles) (Muton-style auto-counterattack?), and a boost to all melee damage from heavy armour. Just a thought.

Rifleman class: with the removal of the Defensive Assault subclass, rifles seem terribly underused, and a rifle-focused class seems to be The Thing on the Workshop (as are Jedi and ninjas). The Ranger's shotgun seems quite superior, and Specialists and Psi-Ops kick butts with your SMGs (but not necessarily firing them). If a rifle-focused class is implemented, its appeal can be much broadened by allowing it to carry LMGs and DMRs instead, as well as using the Sharpshooter pistols or special compact shotguns with built-in EU/EW's CQB ability, and, if it's possible to limit upgrades by weapon type, a certain assault rifle attachment that confers Launch Grenade and Salvo (but not the extra slot). Also, no-one said Muton Centurions can't have that one instead of bayonets...

Now, back to extra weapon tiers. Consider that at the Gauss weapon stage XCOM is still mostly replicating ADVENT tech; they have new rifles, carbines (I hate the name "Stuttergun"), DMRs, cannons, shotguns and a replacement for the revolver, but other weapons do not lend themselves to easy repackaging. This may send Shen looking for alternative applications of the individual components she has learnt to exploit.

The first tech is Unconventional Firearms. It's based on further examination of MEC rockets, and it leads to Lily resurrecting the Gyrojet pistol. She applies the rotation-stabilized gun-launched rocket-propelled grenade design (yes, this is sales pitch for a bolter) to the light pistol and the LMG. The Gyro Pistol is a semi-automatic, packs slightly more punch, but less than the Mag Pistol, and its small explosive rounds have 1 Shred and a chance to Disorient. The Smartgun is a Proving Grounds item, since it requires a MEC's targeting package and crams captured guidance systems into its shells. It's almost as powerful as the Mag Cannon, has much greater accuracy, intrinsic 2 Shred, as well as Covering Fire. It is, however, crippled by the massive magazine housing only 2 shots' worth of rockets. For visual inspiration, one should look at Red Faction: Guerrilla Enforcer rifle.

Emboldened by this success, Shen takes on Laser Weapons. The circuit switchers and capacitors required for effective, portable Gauss weapons are also what is required for effective, portable pulse lasers, which discharge their blast in hundreds of tiny pulses, carving a neat path through the target, rather than just causing a surface explosion that ADVENT personal armour might shrug off.

So, the Proving Grounds can quickly drop a laser pump and medium into the chassis of a magcarbine, rifle or DMR (which would require particularly stupid-looking massive optics). This, however, is not instant win: damage levels are the same or even lower, but accuracy, critical chance and chance of "penetrating dodge" are significantly bumped.

Meanwhile, the Machine Pistol gets overhauled into a simple automatic laser pistol, albeit at the cost of having guaranteed damage. The mini-shotgun is replaced by a disposable charge and medium package and a whole array of optics, resulting in the Fan Beam, with a predictable horizontal spread that is incredibly difficult to evade.

Not all of these weapons make it to plasma tier, and aren't even required to reach it. The pistols get folded into the Beam model, but the legacy of Shen's unorthodox experiments lives on, as she manages to integrate the neurostimulation via plasma effect studied as PEPS and PIKL[www.newscientist.com] before the invasion, causing the new common pistol to have a chance to Stun organics through extremely intense pain. The Fan Beam is supplanted by the Mini Beam Cannon, and the Smartgun is evolved into a Smart Blastgun, a multishot miniaturized blaster launcher which also adds automatic Holo-Targeting to its repertoire of destruction. To further sweeten the pie of having to do research and then build it separately, a side-effect is the creation of a Squadsight-granting weapon attachment.

So, how does it all sound?