Trappers need a limit on either the number of bodies or the amount of mass they can fire their nets clean through.
The single most common cause of wipes on higher difficulty I’ve seen has been caused by a domino-effect of a Trapper standing at the back of a horde, protected from the players frantically shooting at them by all those bodies, and firing a net clean through twenty to thirty entities. This drags one hapless player into the middle of the horde, where all those entities promptly turn around to smack them at once, and the player goes down. Since Trappers run off when a player goes down and are free to web up another player at that point, they have a very quick turn-around time till when they can do this again.
Given the amount of time it takes to reach a downed player buried deep within a mass of bodies - particularly if bad luck means you’re out of grenades (or you’re playing Ogryn with only single-target grenades, or you’re a Psyker with no grenades and your push-back is on cooldown) - this turn-around time is often just the right amount to web up the person who finally fights their way to the downed player. If there are any other Specials or Elites on the field, this can swiftly turn a smooth game where everyone was playing intelligently into a full party wipe.
The situation is even more frustrating when the Trapper is hiding behind a pack of enemy Ogryn, of the sort you can see at higher difficulties. Then, the models are so tall and so massive, it is literally impossible to target a Trapper that runs into their midst.
These are not situations where better play on the party’s part can mitigate this problem. If you can’t form a tight & defensible knot, because it can just snatch you through an entire horde; you can’t come to your teammate’s aid quickly, like you might with a Hound or even like if they were downed normally, because the Trapper pulls them away from you, into the center of that horde; you can’t shoot the Trapper before it gets near, because the mass of an entire horde is protecting it; you can’t hit it in melee because of said mass of the entire horde, plus you are very likely to get webbed if you try; its attack doesn’t do damage to its own allied units in a way that might clear a space, like Flamer or Bomber attacks; and you can’t hide behind cover, like you would against Snipers, because it’s a very mobile Special and will just run around the cover to grab you anyway - then it seems like the Trapper may actually need some tuning.
My suggestion is to put a limit on the number of “allied” entities that the Trapper can fire through - or a limit on the total amount of mass they can fire through, to deal with the “pack of Ogryn” problem.
I can understand why it wouldn’t be a good idea to have their nets be like player projectiles, where a single allied entity in the way can block the shot entirely. There are only three other players to get in your way, while there are dozens of enemies - and the Trapper’s projectile is so wide that, if it couldn’t pass through some “allied” entities, it would almost never get to fire at all. That would be too much. But it needs a “cleave cap” of some kind. Or, if it already has one, it needs to be tuned - because it is not perceptible.
I would also be fine with a Trapper’s webbing becoming something that could trap nearby enemies along with a player, to make it a hazard-to-its-allies Special like Flamers and Bombers. But I suspect that would be even more work. Plus, a “wider net” might create a situation where multiple players get trapped by a single shot - and there are no other Specials where a single one can CC multiple players with a single attack. So, that also might be going too far.
TL:DR - On higher difficulties, a Trapper embedded in a horde - or hiding behind a pack of enemy Ogryn - can quickly become a team-wiping threat with no obvious counter. Can they please have some limitation on the amount of enemies they can fire through effortlessly and without consequence?