You need to spend time studying both Classical chess theory and Hypermodern chess theory. All of the books you listed cover both theories.
Classical Chess Theory(Traditional)-Occupy the center with your pawns and pieces in order to control the center.
Hypermodern Chess Theory(Modern)- Control the center with the power of your pawns and pieces and in this way you do not create targets for your opponent to attack.
I don't understand your last question.
Which should i spend more time studying. Which of these books is modern and which is traiditional
My system
4th edition reassess your chess
mastering chess strategy
giants of strategy
the complete book of strategy
Between modern chess strategy and secrets of modern chess strategy what rating group would you reccommend each book for?