Three Slots
Although many cultivators and demon beast were fighting for the Jade Slips, more than half of the groups without one didn't take part in it. First, because they weren't at the level that they could have a change of keeping it. And second, even if they did get a Jade Slip, they wouldn't be strong enough to protect it after.
As for the Jade Slips owners, only Uer wanted to take part in that fight. But he was stopped by Mino Jan. No one knows what Mino said to convince that maniac to stop from jump right in the middle.
Soon, the difference in power between the groups fighting became apparent, and the ones who knew that they weren't strong enough retreated. In the end, the last two Jade Slips found their new owners. Of course, it wasn't without casualties. In this exchange, over 30 cultivators and demon beasts died.