Hi!

It would really depend on what lineup you use. Since Edo Deidara and Roshi are both Earth Natured, they do benefit from "Earth Style Enhancement", however, note that the Earth Style Enhancement is only for 5 turns. Edo Deidara and Roshi are both very good ninjas and gets stronger the longer the battle lasts.

I personally would recommend using "Pose of Duel" instead and potentially using the other skills in the Crimson Fist's arsenal to make better use of shields to buff ninjas. Also, "Wooden Style - Universal Nature" is a risky but potentially high rewarding move; capable of immobilizing a unit and absorbing 40 chakra.