Yeah names don’t really “make sense” too often. People like to be creative with what kanji are used to represent certain names, lots of names have been around for a long time so they used old readings, and there’s a whole class of readings specifically for names. (I think that’s what namori readings are? Someone will probably correct me on that) You kinda have to learn them as you go. Even natives may not immediately know how to read a name unless it’s a common one - and those you should eventually pick up with enough exposure. It’s not uncommon in books for names to be introduced with furigana that then gets dropped from then on.
Edit: It’s nanori, namori is the name of a manga artist. Oops.