Having an engineering degree myself I would disagree with you. The core classes are much the same plus the higher level classes overlap a bit; calculus 1 - 3, differential equations, physics 1 -3, chemistry 1 - 3, organic chem, etc. The “hard sciences” go more in depth, the engineering goes broader. For example, a chem major may have to take organic chem 1, 2 and 3, but not much physics. An engineering major may take organic chem 1, fluid mechanics, and thermodynamics. Just an example. I suspect that chemical engineering is pretty close to a straight chemistry degree.
Hard science deals with the physical world.
Soft science deals with behaviors and the actions of people.
Industrial Engineers will work with efficiencies and the like and might be considered soft. But someone designing structural supports based material properties, shape of beams, moment connections and the like is definitely in a hard science. It does not mean difficulty; hard means the physical world.
Sorry, but scientists and engineers are completely different career paths. The schools are different. The coursework is different. The certification is different. The job skills are different. The job experience is different. You are talking about similarities of the fundamental undergraduate education, which is not the same as a terminal professional degree or certificate.
A person can take a variety of undergraduate science and math courses, and yet go into the profession of medicine or journalism or business or law. None of these professions would be the same as being a professional scientist. Likewise being an engineer is a different profession than being a scientist. Furthermore, hard scientists are a very specific subset of all scientists.