Sallos has quite a bit of advantage for thieves.
On sallos, we use . remove
on razor, you drag the items quickly out of the pack and release them. If you do it fast enough, your client doesn't load them back into place until you have had time to target or click the item hidden under. Some people stack quite a few items, but its really not any more difficult. You just drag and drop quickly and they will queue up in a way so that you can see the hidden items.
Thieves like to act like their "secrets" are what make a good thief. The truth is that most of their "secrets" are not secrets at all. What makes a good thief is the skill to do multiple things at once, all while looking like you're doing nothing out of the ordinary. Too many thieves just stand next to their target while they snoop through the loot. A good thief isn't noticed until they're off-screen with the items they wanted. A great thief isn't noticed at all. And I'm talking about when your target is actively playing, not afk or looking through their bank box.
IMO, the thieves that can pvp while stealing your shit are the most impressive. There aren't usually too many of those. I could name a few. The pvp community usually knows them well.