You're in a public place, and there are rules to be followed. They aren't following the rules, and it affects everybody, but nobody wants to make a fuss. This leaves the unruly ones to pretty much do whatever they want. Maybe it's not about winning and losing in the regular sense, but it is about trying not to let this type of thing get out of hand. Or are you okay with just letting people walk all over you whenever it suits them, because you don't want to make a scene?
If you just walk away, you might as well write off that area as a place to study, and it's clearly supposed to be a place to study. Next week, they'll be back, with some of their friends. Eventually there will be no more quiet places to study, because no one ever felt like standing up to people who clearly can't follow the rules. Or you could stand up to them.