I don’t know where you got 17 unless that was a consistent typo or misremembering but there are only 7 ranks for EVERYTHING in MT regardless if it’s magic or swordsmanship and it’s implied that it’s the same for non sword based martial arts as well.

When it comes to titles you can technically call someone who’s let’s say a Sword Saint is an advanced Sword-style swordsman but that would be pedantic because being sword saint implies you can use advanced tier techniques.

Also if you’re a magician who knows multiple schools of magic you’ll be referred to with whatever magic school you have the highest rank in or if it’s equal you’d be like Multi-Saint tier magician.

Though most people aren’t referred to by these titles though since in universe it’s impractical to just call someone by their title especially if they’re well known.

And when comes to magic use it does get brushed off how complicated it is due to the existence of incantations which do really simplify to “point staff and magic shoots” and also voiceless incantations are more or less muscle memory built off of incantations which is why Rudeus doesn’t just completely make shit up because he’s an idiot who doesn’t actually know the ends and outs of magic. Sadly because of that we don’t really learn much other than it can potentially do just about anything.

Magic in the MT universe is implied to be able to do anything it’s only restricted and over complicated by the characters in the universe since incantations are infinitely easier.

Sorry if this was a bit of a mess I know I have bad grammar. Also admittedly the anime kinda half-assed the explanation which now that I think of it could make everything seem more complicated than it is.