The Mud Deer were beasts that were known for the way that they attacked. They could use their very bodies as ammunition to spit dense mud balls from a distance. Therefore, Clark was forced to jump and roll multiple times while he tried to get closer.
He didn't have time to worry about Ella because she had caused this issue. He also had two of the mud deer fully focused on him. This issue was slowly remedied by Crim who dashed forward and slashed at the first mud deer.
Crim was able to ignore the potential damage from the mud deer because any of the mud balls they sent at him were nothing to him. The mud balls were too blunt to penetrate his scaled slime body. When he felt the impact he would just be slightly pushed back. And using the increased flexibility that he had, he easily dodged the horns attacking him.