They heard Aslan is strong, he saved people from the rift. But they still think for something so small as this Aslan doesn't deserve to be treated like this.
But they didn't know what the leaders knew. Aslan not only saved everyone from the rift, Aslan and another person cleared the rift all by themselves. Well, it was done mostly by Aslan.
Soon more and more proposals were placed on the tables with better options hoping Aslan would take one. In the end, all of them stopped at the 20% mark where Aslan will be allowed to take 20% of the lots from all the rifts he will raid. And there were also other opportunities and benefits.