I would say you are right and that Earth Style Enhancement would be better seeing as Wooden Style Universal Nature hits a random target which could be either a immune target / dodge target or even a clone and takes their chakra / immobile. This skill only goes off with a shield so if you lose it then there's no point to it. It c*so backfire and immobile you instead or any of your ninjas if they are using kurenai / fire main. So i would say Earth Style Enchanment would be the better choice.