All I can say is that Emma and Naoko pronounce English VERY well and Shigeharu sounds like a Southern Frenchman. I would not worry about my pronunciation. Yo can train this sound and that sound, but when you go to speak you may forget. I still believe that repetitive listening to content and to a voice that you like, especially if the content is lively, will do more for you.
I could not get my tones in Chinese until I started listening to comic dialogues, even when I did not understand. I like the voice, I liked the rhythm and I listened over and over. There is a resonance there that lights some neurons in the brain. Once you are in tune with the music of the language, the intonation, the rest comes naturally.
I pronounce Chinese better today after having learned many languages, than 40 years ago when I only really knew French and English. So continue expanding your brain. Listen to other languages.