First, Stalkers aren't poisonous - you are just bleeding from scars. That makes more sense.
In terms of reality, wouldn't it make less sense that the damage was from wounds bleeding out than a poisonous effect? Because than it should be true for all the specimens, right? The bleeding, that is. But if only the Stalkers are poisonous then it makes kinda sense, right? Like, I am sure a chainsaw would cause bleeding, too. lol.
As a game mechanic I think it's easy to understand the effect from Stalkers as it is now. However, I guess, it would be more
believable that it would be the Crawlers that had this effect on players. BUT as I said, it is easy to understand the effect as it is now with Stalkers,,,and it is just a game.
I guess you could add this effect to the Crawlers with its other effects, alternatively. I think it's just fine as it is now, though.
Edit:
Having tried version 2.0, thanks to poosh, I really like new Husk change. That's a +1.
The Stalker seems to work fine with the new change. I'd might prefer that this change was added to the Crawler instead, and that the blood spatter on the screen turned green like poison. Not that I mind the way it is now.
I do like the bleeding out effect on the players. It's a less deadly blot bile. It stessed that you might need to heal fast, but that you also have (probably) the time to get healed up.
Anyhow, good job on this release!