I am familiar with Shotakan and I agree with you 100%. Learn one discipline and move onto the next. There is one reason why I will learn Krav Maga next. If all goes well, in July, I might be in the Academy for Las Vegas Corrections, if all goes well. This is not maximum security prison, most people here are awaiting trial. You are talking class A B or C misdemeanor petty crimes. However, at time, you will have to restrain inmates. That art deals more with combat situations and it is utilized in military training.
You mentioned music and I will touch on piano and martial arts analogy. I actually was going to go there but good job bringing that up. Now onto that piano. If you can read piano sheet music(treble and base clef notes), know the cords and music theory, then you can move onto the guitar. You can pick any instrument but do not move onto the guitar until you at least reached an advanced level. Same thing with martial arts. I grappled with black betls so I really have the knowledge and experience on and off as a brown. Gracies are notoriously slow if I were anywhere else, I would have been not only a purple but a brown. It's all good you learn the art. I have no need to get a purple brown or black so now it is good to learn an art to subdude inmates. I am sure Mr. Ostad could show me a few basic shotakan moves, HELL I would even pay for his time for ONE private lesson. I can learn the BASICS and tell him the situation. This is more for prison situations how to evade and counter.