Unique Troops: How Hard Can It Be?
Game Design Perspective.
Short answer: Apparently rather hard without taking them from another slot.
Long answer: So the Necron rumours are suggesting a downgrade in armour from 3+ to 4+. Good. This represents an actual effort to make Warriors distinct from Marines in ways other than having a slightly different Feel No Pain.
As it stands, Troops, along with vehicles, are the simplest things to design in 40k. Your basic trooper consists of a statline (divided into MEQ, GEQ and suchlike), a gun (sometimes replaced by or also including a melee weapon) and some basic special rules (that everything else in the army has too, except they're not scoring). So for example, a Marine has MEQ stats, a basic rapid-fire gun effective against things equal to or weaker than it, and the ability to regroup automatically (plus extras like grenades, combat tactics...).
Problems start arising however if this simplicity is taken too far. When different units from different armies begin to become separated by only one or two details, for example. I suppose this is excusable in most Marine armies to a degree, barring Chaos and Grey Knights, but it gets a bit ridiculous when you can play spot the difference between two opposing armies and it's actually quite hard. So, let's see some examples.
Grey Knights are Bloodletters who swapped Furious Charge for a good Save, and their Inv. for a gun.
Daemonettes are flimsy Genestealers that swap Outflank and Deep Strike.
Grey Hunters are the Mycroft to Chaos' Sherlock.
Grot>Conscript>Guardsman is like an evolutionary chain of +1 point each time.
Warrior Henchmen are Guardsmen with sexier options. AND NO GRENADES.
Termagants are like Guardsman with a bolt pistol, weaker armour and Hive control. Unless you give it a Devourer, where it begins to look like the young cousin of the Pink Horror.
I might have been able to find more, but I couldn't be bothered. There are a few Troops left that are, in my opinion, different to the pack. S6 Grey Knights used to be among them, because they were so fundamentally different to a standard Marine (True Grit anyone?). But now fewer and fewer remain. The Tyranid Warrior is uncloned. The Thousand Son unit as a whole is uncloned. The Kroot squad with all its variables is uncloned. The Wych, Kabalite, Fire Warrior, and Ork Boy have just enough quirks to rise above the pack. Crusaders are unique, as are Jokaero (but they still don't make up for the whole Warrior thing.)
All these units have just tiny differentiating quirks. Like the Dark Eldar poison, or the Tau hitting on 4s and wounding on 3s instead of the other way round (against MEQ). The S6 Nemesis halberd was such a quirk, and it died with the old Callidus. Now, I know Red Thirst or Synapse could be considered a quirk, but Synapse can be mitigated and RT is in the whole army. I'm talking about things unique to Troops.
It can't be hard to find other quirks to apply to the other units, can it?
This article was originally going to also include a hints for homebrewers section, but then I realised how long this thing is already by my standards. So there will be a Part 2, where I'll cover all that.