This is exactly right, I am happy to see that someone is using reliable references to clear up such questions. Shihan is a general title referring to instructors of some seniority or respect. Hanshi is a specific title which must be conferred by one's head organization, (if such titles are used).
The idea of being the "model" teacher is the highest form of instruction in traditional martial arts and all other traditional fine arts in Japanese culture. This concept comes from Confucianism in which the teacher or gentlemen-scholar serves as a "model" for all others to follow, imitate and esteem.