Yes Rowson and Marovic are brilliant at giving you the theoretical firepower to come up with creative strokes right when you need them during a game.
Rowson also is known for his observation,
"The only thing you learn from losing is how to lose."
I have several trophies and biggest reason why i got so sick and tired of having my arz handed to me. After getting crushed so many times i knew how to lose. So just stop doing it. When i was starting to win i no exactly what their thinking so mental edge mine. I learned to be humble as i can fall back to that spot so play like it is my last game. I learned who really cared about me playing better. I learned who wanted me on their team and not when i was a good player. I learned if you want respect from your opponent you have to take it by force and leave no doubt they were not on your level. I learned once my opponent is down keep them down. They did that to me in games and it worked so i do it to them.
Yeah i have to say learned absolutely nothing. I heard that several times as i was getting stronger. Patience, patiently i watched them during games when i lost and with time i knew i get stronger. I stay silent. When my game was stronger then theirs at the moment..... Then when i take their money in game and all i heard was silence. 
I think there is something to be said for both a comprehensive treatment of instruction on one hand, and diverse viewpoints on the other. A comprehensive series such as Yusupov's 9 book series (claimed to be "the best instructional chess books in the world" by FIDE) will no doubt cover all the bases of chess play at the risk of being limited to the opinion, playing style and methods of one person. By branching out to other popular and highly rated authors, one might pick up bits and pieces of style and ideas missed from a single author. I'm trying to do a little of both in my book selection, adding to the few old books I accumulated 40 years ago.