While I think Magical Turnabout is generally better,the past section of Turnabout Succession has more to do with the Gramaryes.

Well, the Magical Turnabout's entire plot is Magnifi's fault.. Roger's entire motive has to do with the Gramamyres...

Well,yes,Magnifi definitely has to bear some blame toward the incident,but what Roger does is way too extreme,the guy doesn't know how to "let it go and move on". I personally feel that the past sections of Turnabout Succession definitely has more to do with the Gramaryes,with Magnifi's suicide,him blackmailing his disciples,Thalassa's "death" and so on.