There is a major lack of oversight on Executive Orders.
BUT for the most part they are an accurate use from what I can tell. Usually they are merely aspirational goals for agencies to implement, much more similar to a CEO's quarterly goals for subdivisions. The President is a dual office role of being head of the executive branch, and being head of the military.
I don't really see that much straight up unilateral ordering of specific actions, and those would be the only constitutionally questionable ones.