Only later on will the players need to diversify their damage. Usually, the best choice to go up against enemies in Act I and II is to keep all the character's damage of the same type to all fight the same shield base. This is because when a player deals magically based damage instead they are attacking a different shield.
Due to this class being entirely based around dealing physical damage, the player will likely want to stick to that type of damage base when looking at new skills.