I have largely the same opinion as the accepted answer on this RPG Stackexchange post.
That is, while the enemy is paying attention to you, you are not stealthed, you would not be able to sneakily snatch a pouch or unused weapons. But you can try to cut the straps holding them.
Personally, I would probably rule it like this:
If you actually try to go close in and grab a pouch and hold it in your hands, then after the Sleight of Hand check they get an opportunity attack on you, because you are focused on trying to snatch an object. They notice that opening to strike. And it would use their reaction. But again, this is my personal opinion.