If you put it this way... But I see it like this: I can use that thing. Which means my agents do know how to use it. Once I equip it, I can even see TU costs and accuracy and types of shots, but somehow the article containing this info is hidden from me. This is the only case in the entire game where you don't have a wiki article available for something you CAN use.
No, it's not the only case. There are lots of equipment which you can use even if you haven't researched it yet. In in-game you just don't know the full details of how it works. As an example of possibly 'stranger' item take for example mass driver pistols, rifles, sniper rifles etc. It is apparently fully intentional game design that you unlock the mysteries of the item upon researching it (irrespective if you can use it "blind" or not; some you can, some you can't, and this is also apparently a modder decision).
And I can hardly agree with "but you don't really need all this cultist junk". I wouldn't call that AK rifle I scavenged long before promotion II a "junk I don't even need".
I have played a dozen SH/IM campaigns. I recall only once, in one mission, using AKM or AK, maybe once or twice (as a test, actually), or anything similar. Clearly it's not a necessary item in the meaning that you can well do without it.
Let me expand on my answer to put it in context in case someone finds it useful how you can play the game effectively with very few cultist weapons:
- you want to research non-standard weapons and obtain 'shotgun' ASAP. It's the best very early shotgun, which can reliably one-shot weakly armored cultists with decent range (and deal with most environment alert monsters as well), and you can fit stun rounds into it (enabling easier captures and dealing with, for example, crop circle type missions).
- you can upgrade to double-barrel shotgun and sawed-off for zombie/environmental missions a bit later, or if you know you don't need captures, if you want. Especially against bigger zombie hordes these can be more useful than the regular shotgun.
- when you progress to dealing with safe houses, you will want a longer range gun which can produce good damage in one shot, preferably one-shot killing cultists even if they have some armor and shotgun would no longer work. In the recent update this one-shot-killing is all the more important, because it will prevent spotters from informing the snipers. The earliest weapon you can reliably get is hunting rifle, though its damage leaves much to be desired still.
- quite often rather soon you can upgrade to (or go straight to) bolt action rifle. This you can also reliably get without having to resort to cultist weapons. 30 damage + 0.15 dmg accuracy bonus and 0.9 armor penetration is already rather good (though not perfect) for one-shot kills, if you have, let's say, 80+ accuracy.
- at the cult outpost stage, you should have promo II and be able to obtain sniper rifles. 308 cal is probably best, because with decent bravery, you don't need nowhere near maxed ACC to make decent shots. With sniper rifle stage, you can one-shot kill almost everyone, when you have 80+ ACC, except typically the best armored cultists (and red dawn, who have more HP)
- you will want to have a concealable pistol or SMG a bit later especially for certain undercover missions. Blops pistol is a good example, later to be replaced by smartpistol.
That's essentially all the guns you *need* until 1999. As for other weapons, of course you still want to have specialized ones such as:
- a taser pistol
- some melee weapons stunning and later killing
- after promo II, a grenade launcher and/or MILKOR for stun batons (mostly for easier captures of cultist leaders/commanders etc.)
- CAWS can be a useful upgrade to shotguns
- tactical grenade launchers + gas grenades
- for a couple of missions (rogue tanks etc), something like RPG launcher + anti-tank rockets.
So out of ~100(?) earth-based weapons, you just need ~10 and you're done.
