Mr Gnar: Wet Screams are very specificly for sloppy mud, the long spikes on an uncut WetScream is terrifying on rocks and roots. Only really used on DH tracks covered in gravy like mud, and long grassy finishes through fields.
That's what they are intended for. Sure. Doesn't mean they don't provide incredible grip in most wet riding conditions, which they do – in spades. I got over my fear of riding at speed over wet roots a good while ago and barely notice the spikes lack of grip there unless I hesitate.
High Rollers were apparently designed for "loose over hard pack" whatever that is, that's how they used to be categorised if I recall correctly, but I find them a great all year, all condition tyre, with the obvious exception of very wet weather…when I don the wet screams and usually listen to a chorus of people moaning "oh thats not fair, you've got spikes on..I have no grip etc etc etc".
No need to stick dogmatically to the manufactures description. They often change anyway.