Recently, the people over at the Japanese GGXX BBS have put together a matchup diagram for Accent Core Plus R! Each of the character threads were asked to make a matchup list for their respective characters, and the data was compiled into one chart. There was also some kind of adjustment done to the numbers if there were disagreements on certain matchups(the Johnny and Slayer threads disagreed on what the exact MU number was, for example). This is why the data is perfectly symmetrical in the chart.

Anywho, this is the latest post containing a full chart on the thread. I went ahead and translated it here since the board likes to use those single kanji abbreviations for characters. I like how Anji is represented with the kanji for nude lol. Advantageous matchups are colored in blue, and disadvantageous matchups are red.