They perfectly timed their attacks and successfully dealt with the first zombie dog they encountered.
When the other 2 zombie dogs appeared, they divided their groups into 2 and dealt with the zombie dogs.
All of them needed to cooperate with some people just to deal with three zombie dogs. It shows that their ability level was still very low.
If their abilities were at a higher level, they wouldn't need to cooperate with others, and they could just deal with it on their own.
Well, if they had used their guns, they might have dealt with the zombie dogs immediately, but they were afraid that the gunshots would be heard by others and join the fray.
It would be bad for them if there were more zombie animals around. So, they didn't use guns but just used their abilities and other weapons.
"Hurry up and look for vegetables and other plants. We can't stay here for long," Treyton ordered after dealing with the zombie dogs.